Method and apparatus for gastrointestinal tract ablation to achieve loss of persistent and/or recurrent excess body weight following a weight-loss operation

ABSTRACT

Devices and methods are provided for ablational treatment of regions of the digestive tract in post-bariatric surgery patients who fail to achieve or maintain the desired weight loss. Bariatric procedures include Roux-en-Y gastric bypass, biliopancreatic diversion, and sleeve gastrectomy. These procedures reconstruct gastrointestinal tract features, creating pouches, stoma, and tubes that restrict and/or divert the digestive flow. Post-surgical dilation of altered structures is common and diminishes their bariatric effectiveness. Ablation of compromised structures can reduce their size and compliance, restoring bariatric effectiveness. Ablation, as provided the invention, starts at the mucosa and penetrates deeper into the gastrointestinal wall in a controlled manner. Control may also be provided by a fractional ablation that ablates some tissue within a target region and leaves a portion substantially unaffected. Embodiments of the device include an ablational electrode array that spans 360 degrees and an array that spans an arc of less than 360 degrees.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 60/958,543, filed on Jul. 6, 2007, entitled “Non-Barrett's MucosalAblation and Tissue Tightening Indications Related to Obesity” by DavidS. Utley.

This application incorporates in entirety commonly assigned U.S. patentapplication Ser. No. 10/370,645 entitled “Method of Treating AbnormalTissue in the Human Esophagus”, filed on Feb. 19, 2003, and published asUS 2003/0158550 on Aug. 21, 2003, and U.S. patent application Ser. No.11/286,444 entitled “Precision Ablating Method”, filed on Nov. 23, 2005,and published as US 2007/0118106 on May 24, 2007. Further, each of thefollowing commonly assigned United States Patent Applications areincorporated herein by reference in its entirety: patent applicationSer. No. 10/291,862 titled “Systems and Methods for Treating Obesity andOther Gastrointestinal Conditions,” patent application Ser. No.10/370,645 titled “Method of Treating Abnormal Tissue In The HumanEsophagus,” patent application Ser. No. 11/286,257 titled “PrecisionAblating Device,” patent application Ser. No. 11/275,244 titled“Auto-Aligning Ablating Device and Method of Use,” patent applicationSer. No. 11/286,444 titled “Precision Ablating Device,” patentapplication Ser. No. 11/420,712 titled “System for Tissue Ablation,”patent application Ser. No. 11/420,714 titled “Method for CryogenicTissue Ablation,” patent application Ser. No. 11/420,719 titled “Methodfor Vacuum-Assisted Tissue Ablation,” patent application Ser. No.11/420,722 titled “Method for Tissue Ablation,” patent application Ser.No. 11/469,816 titled “Surgical Instruments and Techniques for TreatingGastro-Esophageal Reflux Disease.” This application further incorporatesin entirety U.S. patent application Ser. No. 10/291,862 of Utley, filedon Nov. 8, 2002 entitled “Systems and Methods for Treating Obesity andOther Gastrointestinal Conditions, and published on May 13, 2004 as US2004/0089313, and U.S. Pat. No. 7,326,207 of Edwards, entitled “SurgicalWeight Control Device”, which issued on Feb. 5, 2008. This applicationfurther incorporates in entirety U.S. patent application Ser. No.12/114,628 of Kelly et al. entitled “Method and Apparatus forGastrointestinal Tract Ablation for Treatment of Obesity”, as filed onfiled May 2, 2008. This application further incorporates in entiretyU.S. patent application Ser. No. 12/143,404, of Wallace, Garabedian, andGerberding, entitled “Electrical Means to Normalize Ablational EnergyTransmission to a Luminal Tissue Surface of Varying Size”, as filed onJun. 20, 2008.

INCORPORATION BY REFERENCE

All publications, patents and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent or patent application wasspecifically and individually indicated to be incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to endoscopic therapy devices and methods,such as devices and methods to treat areas of the digestive tract inoverweight and obese patients who have undergone weight loss surgery(bariatric surgery), yet failed to achieve or maintain the desiredexcess body weight loss.

BACKGROUND OF THE INVENTION

Obesity can lead to a number of life-threatening and morbidity-producingdisease states such as diabetes mellitus, heart disease, vasculardisease, osteoarthritis, gout, and obstructive sleep apnea. Body massindex [kg body mass/(meters height)²] is used as a measure of obesity; apatient with a BMI of 25.0-29.9 kg/m² is considered overweight, while aBMI greater than 30.0 kg/m² considered obese. If diet and exercise areunsuccessful in achieving or maintaining an optimal or ideal bodyweight, and if the patient has a BMI greater than 40 kg/m² (or a BMIgreater than 35 kg/m² with coexisting morbid conditions), a bariatricsurgical procedure may be performed to induce weight loss. Bariatricsurgeries are generally categorized as having a restrictive effect, amalabsorptive effect, or both effects. A restrictive effect refers tocreating a surgical constriction at the area where food exits theesophagus or proximal stomach and/or reducing the size of the stomach,which acts a food reservoir. By restricting exit of food from theesophagus and proximal stomach and by restricting the size and/orcompliance of the stomach, the stomach (or its remnant) fills with asmall amount of food and the patient experiences early fullness orsatiety. Such an effect either makes it uncomfortable to eat additionalfood or diminishes appetite (induces satiety). A malabsorptive effectrefers to changing the digestive tract anatomy so that absorption ofnutrients from food intake is limited or altered in some manner and/orthe intake of excessive amount of food causes the patient to haveadverse symptoms. In addition to these effects of bariatric surgery thatare related to surgically altered digestive tract anatomy, other effectson endocrine and neural systems that include the gastrointestinal tracthave also been recently appreciated as having significant anti-obesityor anti-diabetic effects (see U.S. patent application Ser. No. 12/114628of Kelly et al., filed May 2, 2008).

The most common bariatric surgical procedure performed is the Roux-en-Ygastric bypass (RGB), which is considered both a restrictive andmalabsorptive procedure. Other techniques, performed less commonly,include sleeve gastrectomy and biliopancreatic diversion (BPD). Eachoperative technique has a physiological effect that is related to thepost-surgical reconstructed anatomy. An anatomical structure common tothe RGB and BPD is a small pouch at the end of the esophagus, formedfrom a portion of the proximal stomach and then connected in a newmanner to a portion of the small intestine via a structure known as astoma (typically a gastrojejunostomy stoma). Similarly, the sleevegastrectomy permanently removes a large portion of the body of thestomach, creating a narrow tubular stomach that empties into the smallintestine. The pouch and stoma of the RGB and BPD, as well as the tubeof the sleeve gastrectomy, all restrict the flow of food passage fromthe esophagus to the rest of the digestive tract, thus causing asensation of early fullness or satiety. Further, while the stomach canhold large amounts of food, the capacity of the surgically-formedgastric pouch or sleeve is quite limited, and thus the patient cannottake in large quantities of food and liquids due to a low reservoircapacity. Malabsorption is also an important effect of bariatricsurgical procedures, which contributes to cause weight loss, in additionto the restrictive effects of these procedures.

The reported effectiveness of RGB and other such operations is quitehigh, with patients losing an average of 60-70% of their excess bodyweight within about one year. Excess body weight is the amount of bodymass above the ideal body weight for a patient, while excess body weightloss is the percentage of the excess body weight that is lost as aresult of the surgical intervention for a patient. A successfulbariatric surgical procedure is considered one in which the patientachieves>50% excess body weight loss. Some patients fail to ever achievea 50% excess body weight loss at any time after surgery, although thisrepresents the minority of patients. Within the initial surgicalsuccesses, approximately 25% of patients regain all or a significantportion of the previously lost weight and are then considered surgicalfailures. The reasons for weight regain may include dilation of thepouch and/or stoma in the case of the RGB and BPD, while in gastricsleeve resection patients the newly tubularized stomach may dilate. Inall three scenarios, more food is able to be stored in the pouch andtubularized stomach due to dilation, therefore early satiety is notachieved, and the food may pass more quickly into the small intestine,therefore making more room for more food to be eaten. Dilation can beobserved in endoscopic examination where the structure appears visiblylarger in one or more dimensions, specifically inner diameter, than theideal size achieved at prior surgery. Dilation can result from anincrease in compliance or distensibility of the structure, which is notdetectable on endoscopic examination. Increased compliance of thepouch/tube will allow the structure to stretch to accommodate more foodand liquid, while increased compliance of the stoma will allow food andliquid to pass more readily. In both cases, there is a loss of thesensation of early satiety which allows the person to take in largerquantities of food and liquid at more frequent intervals, thus resultingin regain of weight.

For patients that have undergone a bariatric surgical procedure and haveregained some or all of their excess body weight, the options foradditional therapy to re-achieve weight loss are very limited. A repeatsurgical procedure to revise the altered gastrointestinal anatomycarries a very high risk for surgical morbidity and mortality. Suchrevision surgical procedures might alter the pouch and stoma, or mightalter the gastric tube, but with uncertain results. These types ofrevisional procedures are not commonly performed due to patient risk.Others have attempted a non-surgical, endoscopic revision procedure withthe placement of endoscopic suture material and other such mechanicalstructures to reduce the size of the pouch/stoma and gastric tube,although these are temporary interventions. When the suture or structurefalls out or is absorbed by the body, the previously dilated anatomy mayrecur and weight gain return. Therefore, a viable, non-surgical,endoscopic device and method which would result in a permanentalteration of the stoma/pouch and gastric sleeve which would reduce thesize and/or compliance of the structure(s), would be desirable.

SUMMARY OF THE INVENTION

The present invention provides various embodiments of an endoscopictherapeutic device and method to achieve a permanent physiologicalalteration of the stoma/pouch and gastric sleeve in a previouslyoperated patient after Roux-en-Y gastric bypass (RGB), biliopancreaticdiversion BPD), or gastric sleeve resection for overweight and obeseindications, in order to reduce the size and/or compliance of thestructure(s) and re-establish weight loss and ideal body weight for thepatient. Rather than relying on foreign body material, such as sutureand staples, to achieve this permanent alteration, the disclosed devicesand methods alters the anatomy with ablative therapy thus allowing thebody's healing processes to incur a change in size, shape, andcompliance to re-establish weight loss. To this end, the device includesan endoscopic catheter that is either balloon-based or notballoon-based, and, is mounted on the end of an endoscope, passesthrough a working channel or accessory channel of an endoscope, orpasses along side an endoscope. The device has an energy deliveryelement, such as an electrical array, on at least one surface to deliverablational energy from a source to the targeted tissue in a manner sothat the depth of ablation is controlled via parameters such as energydensity, electrode pattern, power density, number of applications, andpressure exerted on the tissue. The catheter is supplied with ablationenergy by an energy generator, connected to the catheter with a cable.

The method includes using the devices described, typically inconjunction with an endoscope for visualization, to visualizegastrointestinal features that have been formed, altered, orreconstructed by bariatric surgery, positioning the device in one ormore locations with the described structures, deploying the device so asto make therapeutic contact with the described structures, anddelivering ablative energy one or more times. Treatment parameters maybe such that a uniform level of ablation is achieved in all or part ofthe structure. For example, the entire epithelium can be removed fromthe structure, without injury to deeper layers of the structure, thusresulting in healing in a narrowed and/or less compliant state overtime. Another example is to apply energy in a uniform manner to incur adeeper injury, including the deep mucosa and submucosa, with attendantheating of connective tissue, collagen-rich tissue in particular, heatmediated contraction of those structures and shrinkage of the structure.The method may include more than one mechanism of action, such asepithelial layer partial or complete removal, as well as heat-mediatedtissue contraction. All mechanisms of action result in a reduction ofthe size of the treated structure, both immediately and over a longertime course, and/or a reduction in compliance of the structure(immediately and over time), with the desired result of re-establishingand maintaining weight loss for the patient.

A number of ablation devices are provided as examples of embodimentsthat provide either fully-circumferential or partially-circumferentialablation surfaces. These, however, are merely examples and otherembodiments that are consistent with the characterization of havingfully-circumferential or partially-circumferential ablation surfaces areincluded as embodiments. Further, the effects of ablation on features ofa gastrointestinal tract that have been formed by a bariatric surgerythat are described in the context of one particular embodiment of theinvention are generally intended to apply to the effects as achieved byany embodiment. Further still, the fractionally-ablating radiofrequencyelectrode patterns or associated methods of operating them may beapplied to any embodiment, regardless of whether the ablation surface isfully or partially circumferential.

The invention provides a system and methods for implementing the systemto ablationally treat tissue in a target area of a gastrointestinaltract feature formed by a bariatric procedure that has failed in itsobjective of having a patient achieve loss of excess weight. Typically,such surgical failure includes the dilation of a feature formed by theweight loss therapy. The method includes delivering radiofrequencyenergy to a tissue surface in the target area (the target area being acontiguous radial portion of an anatomical structure formed or alteredby the bariatric procedure) and controlling the delivery ofradiofrequency energy across the tissue surface in the target area andinto tissue layers in the target area. Exemplary bariatric proceduresinclude any of a Roux-en-Y procedure, a biliopancreatic diversion, asleeve gastrectomy, or any similar procedure. Exemplary features of agastrointestinal tract formed by bariatric procedure include any of agastric pouch, a stoma, or a gastric sleeve. A particular exemplaryfeature may include a suture or staple line of the gastric sleeve. Anexemplary mode of delivering radiofrequency energy includes deliveringradiofrequency energy from non-penetrating electrodes.

In some embodiments of the method, controlling the delivery ofradiofrequency energy across the tissue surface in the target areaincludes delivering sufficient radiofrequency energy to achieve ablationin one fraction of the tissue target surface and delivering insufficientradiofrequency energy to another fraction of the surface to achieveablation. In some of these embodiments, controlling the fraction of thetarget area surface that receives sufficient radiofrequency energy toachieve ablation includes configuring the electrode pattern such thatsome spacing between electrodes is sufficiently close to allowconveyance of a level of energy sufficient to ablate and other spacingbetween electrodes is insufficiently close to allow conveyance of thelevel of energy sufficient to ablate. In other embodiments, controllingthe fraction of the target area surface that receives sufficientradiofrequency energy to achieve ablation includes operating theelectrode pattern such that the energy delivered between some electrodesis sufficient to ablate and energy sufficient to ablate is not deliveredbetween some electrodes. In some embodiments of the method, thedelivering energy step is performed more than once, as may beappropriate for treatment of the target site.

In some embodiments of the method, controlling the delivery ofradiofrequency energy into tissue layers includes controlling thedelivery of radiofrequency energy from the tissue surface such thatsufficient energy to achieve ablation is delivered to some layers,particularly shallow layers, and insufficient energy is delivered toother layers, particularly deeper layers, to achieve ablation. In someembodiments controlling the delivery of radiofrequency energy across thesurface and into tissue layers in the target area is such that somefraction of the tissue volume is ablated and another fraction of thetissue volume is not ablated. In more specific terms regarding thetissue layers being ablated, going from shallow to deep, controlling thedelivery of energy into tissue layers may consist variously of ablatinga fraction of tissue in the epithelial layer; ablating a fraction oftissue in the epithelial layer and the lamina propria, ablating afraction of tissue in the epithelial layer, the lamina propria, and themuscularis mucosae; ablating a fraction of tissue in the epitheliallayer, the lamina propria, the muscularis mucosae, and the submucosa; orablating a fraction of tissue in the epithelial layer, the laminapropria, the muscularis mucosae, the submucosa, and the muscularispropria. More generally, controlling the delivery of radiofrequencyenergy across the tissue surface and into tissue layers can causefractional ablation in tissue layers of the gastrointestinal tract.

In some embodiments of the method, delivering energy includes deliveringenergy from an electrode pattern configured circumferentially through360 degrees around an ablation structure. In some of these embodiments,delivering energy from the ablation structure includes transmittingenergy asymmetrically through the 360 degree circumference such thatablation is focused in an arc of less than 360 degrees. In otherembodiments, delivering energy includes delivering energy from anelectrode pattern configured circumferentially through an arc of lessthan 360 degrees around the ablation structure.

Some embodiments of the method may further include evaluating the targetarea at a point in time after the delivering energy step to determinethe status of the area. The evaluating step may occur in close timeproximity after the delivery of energy, to evaluate the immediatepost-treatment status of the site. In various embodiments, theevaluating step occurs at least one day after the delivery of energy.

Some embodiments of the method may further include deriving energy fordelivery to the target area from an energy source that is controlled bya control system. In some of the embodiments, the energy source is agenerator. Various of these embodiments may further include feedbackcontrolling the energy transmission so as to provide any of a specificpower, power density, energy, energy density, circuit impedance, ortissue temperature.

Some embodiments of the method may further include advancing an ablationstructure into the alimentary canal (wherein the non-penetratingelectrode pattern is on the structure, and the structure is supported onan instrument); positioning the ablation structure adjacent to thetarget area; and moving the ablation structure toward the surface of thetarget area to make therapeutic contact on the target area prior todelivering energy. In various of these embodiments, the moving step mayinclude any of inflating a balloon member, expanding a deflectionmember, moving a deflection member, or expanding an expandable member.

In some embodiments of the method, following the moving step, the methodmay include a position-locking step following the moving step; anexemplary position-locking step may include developing suction betweenthe structure and the ablation site.

In some embodiments of the method, prior to the positioning step, mayinclude evaluating the target area in order to determine the status ofthe target area.

Some embodiments of the method include treating multiple target areas,in which case the method may include the positioning, moving, andtransmitting energy steps to a first target area, and then furtherinclude directing the positioning, moving, and transmitting energy stepsto another target area without removing the ablation structure from thepatient.

As mentioned at the outset of the summary, embodiments of the inventioninclude an ablation system for treating a target area in tissue in aportion of a gastrointestinal tract formed by bariatric procedure. Sucha system includes an electrode pattern including a plurality ofelectrodes; a longitudinal support member supporting the electrodepattern; a generator coupled to the plurality of electrodes; and acomputer controller in communication with the generator. The controllerhas programming to direct the generator to deliver energy to theplurality of electrodes, the programming including the ability to directdelivery of energy to a subset of the electrodes, the electrodes of thepattern configured such that, when receiving energy from the generatorand in therapeutic contact with a tissue target area, the electrodesablate a portion of tissue in the target area and leave a portion oftissue in the target area non-ablated. Exemplary portions of thegastrointestinal tract formed or altered by the bariatric procedureinclude any of a gastric pouch, a stoma, or a gastric sleeve

In some embodiments of the ablation system, the electrode pattern,having a longitudinal axis aligned with the endoscope or the supportingdelivery catheter, forms a fully circumferential surface orthogonal toits longitudinal axis, the pattern sized for contacting tissue in atarget area in the gastrointestinal tract. In other embodiments, theelectrode pattern forms a partially circumferential surface orthogonalto its longitudinal axis, the pattern being appropriately sized forcontacting tissue in a target area in the gastroinstestinal tract. Invarious of these latter embodiments, the electrode pattern forms an arcof about 180 degrees, and in other embodiments, the electrode patternforms an arc of about 90 degrees.

In some embodiments of the ablation system, electrode elements aredistributed into a pattern such that when the programming directs thegenerator to deliver energy to all the electrodes, the electrodepattern, when therapeutically contacted to a target tissue area, ablatesa portion of tissue in the target area and does not ablate anotherportion of tissue in the target area. In other embodiments, theprogramming directs the generator to deliver energy to a subset ofelectrode elements that form a pattern which, when therapeuticallycontacted to a target tissue area, ablates a portion of tissue in thetarget area and does not ablate another portion of tissue in the targetarea. By either approach, using all of the electrodes of a fractionaldistribution, or using a portion of the electrodes that are distributedinto a fractional pattern, the system can effect an ablation wherein theportion of tissue which is ablated is rendered at least partiallydysfunctional, and wherein the portion of the tissue which is notablated retains its functionality.

Some embodiments of the invention include an ablation system fortreating targeted tissue in a target area of a gastrointestinal tractfeature formed by a bariatric procedure that has failed. Such a systemmay include an ablation structure supported by an instrument, anelectrode pattern on the ablation support structure, the electrodepattern configured to control the delivery of energy to a target tissuesuch that a portion of the surface of the target area receivessufficient radiofrequency energy to achieve ablation and another portionof the surface of the target receives insufficient energy to achieveablation; and a means supported by the instrument by which to bring theablation structure to gain therapeutic contact with tissue at the targetarea.

In another aspect of the therapeutic method provided herein, the methodis one of non-surgically treating a gastrointestinal tract featureformed by a bariatric surgical procedure that has become dilated oroverly-compliant. Such method includes identifying a target area of thesurgically-formed gastrointestinal feature, positioning a therapy devicein the gastrointestinal tract adjacent to a target area on the dilatedfeature, and performing a non-surgical reduction therapy on the targetarea of the dilated feature. In some embodiments, the identifying stepis performed endoscopically. And in some embodiments, the identifyingstep, the positioning step, and the performing step are all conductedduring a single endoscopic procedure. Embodiments of the method mayfurther include inserting an instrument having a reduction therapydevice mounted thereon into the gastrointestinal tract before theidentifying step, and removing the instrument after the performing step.

Embodiments of this method of performing the non-surgical reductiontherapy on the surgically-formed gastrointestinal feature may includeapplying energy, such as radiofrequency energy to the target area.Further, the application of energy may include applying energy more thanonce, and it may include applying energy to more than one site on thegastrointestinal feature during a treatment, or in multiple sessions oftreatment. Per embodiments of the invention, applying energy also mayinclude controlling the delivery of energy across the tissue surface inthe target area, and it may also include controlling the depth ofdelivery of energy into tissue layers in the target area.

Embodiments of this method of performing the non-surgical reductiontherapy on the surgically-formed gastrointestinal feature, alternativelyto radiofrequency energy, may include applying cryogenic treatment tothe target area. In some of these embodiments, the cryogenic treatmentincludes spraying a cryogenic fluid on the target area, and in otherembodiments, the cryogenic treatment includes drawing heat from thetarget area into a cryogenic fluid contained in the device

In some embodiments of the method, the positioning step may furtherinclude moving an ablation structure of the device so as to maketherapeutic contact with a target area on the dilated feature. Exemplaryways of moving the ablation structure may include any of inflating aballoon member, expanding a deflection member, moving a deflectionmember, or expanding an expandable member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D provide a view of a portion of a gastrointestinal tract thathas been reconstructed by either a Roux-en-Y bypass procedure (RGB) or abiliopancreatic diversion (BPD); the view includes the esophagus, thenproceeding distally, the gastroesophageal junction, a gastric pouch, astoma or anastomosis between the gastric pouch and a portion of thesmall bowel, and a portion of the small bowel itself. FIG. 1A shows anablative device with a fully circumferential operating radius insertedinto the gastric pouch, filling the lumen of the pouch.

FIG. 1B shows an ablative device with a partially circumferentialoperating radius inserted into the gastric pouch, and positioned againsta portion of the wall.

FIG. 1C shows an ablative device with a fully circumferential operatingradius inserted into the stoma, filling the lumen of the stoma.

FIG. 1D shows an ablative device with a partially-circumferentialoperating radius inserted into the stoma and positioned against aportion of the stomal wall.

FIGS. 2A-2B provide a view of a portion of a gastrointestinal tract thathas been reconstructed by a sleeve gastrectomy. The esophagus andgastroesophageal junction are similar to that of the RGB or BPDprocedures as seen in FIGS. 1A-1C; the focus is on the gastric sleeveformed by suturing or stapling a tubular portion from the stomach,effectively removing the majority of the stomach from the digestive flowpath for. FIG. 2A shows an ablative device with a fully circumferentialoperating radius inserted into the gastric sleeve, filling the lumen ofthe sleeve.

FIG. 2B shows an ablative device with a partially circumferentialoperating radius inserted into the gastric sleeve, and positionedagainst a portion of the wall of the sleeve.

FIG. 3 is a flow diagram depicting an overview of the method, wherein anappropriate site for ablational treatment of dilated feature of agastrointestinal tract formed by bariatric surgery is determined, thelevel of ablational therapy is determined, and at least preliminaryinformation is gained regarding localization, and clinical judgment isexercised as to which embodiment of the invention is preferable.

FIG. 4 is a flow diagram depicting the method after the site of ablationof a portion of the bypass-reconstructed tract has been localized and achoice has been made regarding the preferred ablational device. Themethod includes an evaluation of the site, including particulars oflocation, stage, determination of the number of sites, and thedimensions. The method continues with insertion of the instrument andits movement to the locale of the ablational target tissue, the morerefined movement of the ablational structure that create atherapeutically effective contact, the emission of ablational radiationand then post-treatment evaluation.

FIG. 5 is a view of an embodiment of an ablative device with a fullycircumferential operating radius.

FIG. 6 is a view of an embodiment of an ablative device with a fullycircumferential operating radius, with a balloon member in an expandedconfiguration.

FIGS. 7A-7C show the electrode patterns of the device of FIG. 5.

FIGS. 8A-8D show electrode patterns that may be used with embodiments ofthe ablative device with a fully circumferential operating radius, orwith any device embodiments described herein.

FIG. 9 is a view of the ablation device of the invention with apartially circumferential operating radius.

FIG. 10 is an end view of the ablation device embodiment of FIG. 9.

FIG. 11 is an end view of the device of FIG. 9 in an expandedconfiguration.

FIGS. 12, 13, and 14 are end views of the device of FIG. 9 inalternative expanded configurations.

FIG. 15 is a view of the ablation device of the invention in anunexpanded configuration.

FIG. 16 is a view of the ablation device of the invention in an expandedconfiguration.

FIGS. 17 and 18 are end views of the device in an expandedconfiguration.

FIG. 19A is a view of the ablation device of the invention showing adeflection member feature.

FIG. 19B is a view of the ablation device of the invention showing analternative deflection member wherein the device is in an expandedconfiguration.

FIG. 20 is a view of device shown in FIG. 19B wherein the deflectionmember is in an unexpanded configuration.

FIG. 21 is an end view of the device in an unexpanded configuration.

FIG. 22 is an end view of the device shown in FIG. 21 in an expandedconfiguration.

FIG. 23 is a view of the ablation device of the invention showing apivoting ablation structure feature.

FIG. 24 is an illustration of the ablation device of the inventioncombined with an endoscope system.

FIG. 25 is a schematic of view of a section through the wall of arepresentative organ of the bypass-reconstructed gastrointestinal tract,such as a gastric pouch, stoma or tubular portion.

FIG. 26 is a view of the ablation device of the invention including anelongated sheath feature.

FIG. 27 is a view of the device wherein an elongated sheath feature isoptically transmissive.

FIG. 28 is an enlarged view of the optically transmissive feature of thedevice.

FIG. 29 is a cross sectional view of the optically transmissive sheathfeature of the device shown in FIGS. 27 and 28.

FIG. 30 is a view of the device including an alternative opticallytransmissive sheath feature and an inflation member feature in anexpanded configuration.

FIG. 31 is an illustration of the ablation device of FIG. 30 positionedwithin an esophagus.

FIG. 32 is a view of the ablation device of the invention including aslit sheath feature.

FIG. 33A is an end view of a slit sheath feature of the device whereinthe sheath is in an unexpanded configuration.

FIG. 33B is an end view of a slit sheath feature of the device and anendoscope wherein the sheath is in an expanded configuration.

FIG. 34A is a cross sectional view of the device positioned within anendoscope internal working channel wherein an inflatable member featureis in an unexpanded position.

FIG. 34B is a view of the device shown in FIG. 34A wherein theinflatable member feature is in an expanded position.

FIG. 35A is a cross sectional view of the device positioned within anendoscope internal working channel wherein an expandable member featureis in an unexpanded position.

FIG. 35B is a view of the device shown in FIG. 35A wherein theexpandable member feature is in an expanded position.

FIG. 36A is a cross sectional view of the device positioned within anendoscope internal working channel wherein an alternative expandablemember feature is in an unexpanded position.

FIG. 36B is a view of the device shown in FIG. 36A wherein theexpandable member feature is in an expanded position.

FIG. 37 is a view of the ablation device of the invention including analternative deflection member.

FIG. 38 is an illustration of the ablation device of the inventionincluding an alternative deflection member positioned within the lumenof an organ of the bypass-reconstructed gastrointestinal tract in anon-deflected position.

FIG. 39 is an illustration of the device shown in FIG. 38 wherein thedeflection member is in a deflected position.

FIG. 40 is a cross sectional view of the ablation device of theinvention showing an internal coupling mechanism feature.

FIG. 41 is a cross sectional view of the ablation device of theinvention showing an alternative internal coupling mechanism and arolled sheath feature.

FIG. 42 is an illustration showing a cross sectional view of theablation device of the invention positioned within the lumen of an organof the bypass-reconstructed gastrointestinal tract.

FIG. 43 is an illustration of the ablation device of the inventionpositioned within an esophagus showing a rotational feature.

FIG. 44 is an illustration of the ablation device of the inventionpositioned within an esophagus showing a rotational feature combinedwith an inflation member in an expanded configuration.

FIGS. 45A-45C are views of the ablation device of the invention showingalternative rotational features.

FIG. 46A is a view of an endoscope.

FIG. 46B is a view of the ablation device of the invention including acatheter feature.

FIG. 46C is a view of a sheath feature of the device.

FIG. 47 is a view of the ablation device of the invention including thefeatures shown in FIGS. 46A-46C in an assembly.

FIGS. 48A-48D show an electrode array with a striped pattern for afractional ablation and the ablation patterns on tissue that can be madefrom such a pattern.

FIGS. 49A and 49B show an electrode array with a concentric-circlepattern for a fractional ablation and the ablation patterns on tissuethat can be made from such a pattern.

FIGS. 50A and 50B show an electrode array with a checkerboard patternfor a fractional ablation and the ablation patterns on tissue that canbe made from such a pattern.

FIGS. 51A and 51B show an electrode array with a checkerboard patternoperating in a non-fractional manner and the ablation pattern on tissuethat is made from such an operating pattern.

FIGS. 52A and 52B show an electrode array with a checkerboard patternoperating in a fractional manner and the ablation pattern on tissue thatis made from such an operating pattern.

FIGS. 53A and 53B show an electrode array with a striped pattern ofalternating positive and negative electrodes operating in anon-fractional manner and the ablation patterns on tissue that can bemade from such an operating pattern.

FIGS. 54A and 54B show an electrode array with a striped pattern ofalternating positive and negative electrodes operating in a fractionalmanner and the ablation patterns on tissue that can be made from such anoperating pattern.

FIG. 55 shows a schematic rendering of a three-dimensional view of atarget region of a radial portion of a bypass-reconstructedgastrointestinal wall after it has been ablationally treated.

FIG. 56A and 56B provide views of an ablational device (similar to thedevices of FIGS. 38 and 39) but including an ablational surface on ahinge structure or deflecting mechanism similar to that depicted in FIG.43, the hinge allowing a free pivoting movement of the ablationalsurface between its longitudinal axis and the longitudinal axis of anendoscope. FIG. 56A shows the device with the ablational surfaceoriented in parallel with the endoscope. FIG. 56B shows the device withthe longitudinal axis of the ablational surface oriented at about aright angle with respect to the longitudinal axis of the endoscope.

FIG. 57A-57D provide perspective views of an ablation device with a 360degree circumferential ablation surface on an overlapping electrodesupport furled around an expandable balloon, the operative elementincluding a balloon and an electrode support in an expanded state. FIG.57A shows the support pulled away from the balloon to clarify that aportion of the support and an edge is adherent to the balloon, andanother portion and its edge is not connected to the balloon.

FIG. 57B shows the operative element of the device with the non-adherentportion of the support furled around the balloon in a deployableconfiguration, the non-adherent portion and its edge overlapping aroundthe adherent portion.

FIG. 57C shows the device of FIGS. 57A and 57B with an optional featureof the operative element, one or more elastic bands wrapped around theelectrode support.

FIG. 57D shows the device of FIG. 57C in a collapsed state, with balloonportion being uninflated (or deflated), this being the state of thedevice when it is being deployed into a lumen and being positioned at atarget site, as well as the state of the device after deliveringablation energy and about to be removed from the lumen.

FIGS. 58A-58B depict an embodiment of an ablation device that is adaptedto present an ablational surface into a concave or inwardly taperedtarget site such as the pylorus. The device includes an ablationalsurface circumferentially arranged on the distal portion of anexpandable member, the expandable member mounted around the distal endof an endoscope. FIG. 58A shows the device in a deployed configuration.

FIG. 58B shows the device with the expandable member in an unexpanded orcollapsed state, as would be appropriate for deployment of the device toa target tapered surface, or as would be appropriate for removal fromthe ablational site.

DETAILED DESCRIPTION OF THE INVENTION

Ablation Treatment of Structures within the Gastrointestinal Tract thathave been Altered by a Bariatric Surgical Procedure

U.S. patent application Ser. No. 12/114628 of Kelly et al., filed May 2,2008, provides methods and systems for the use of ablation at varioussites in the gastrointestinal tract as a primary therapy for diabetesand morbid obesity. The present application provides methods and systemsfor ablation as a secondary, a rescue, or a salvaging therapy in thewake of a failed surgical approach to obesity such as may occur inRoux-en-Y gastric bypass, biliopancreatic diversion, and sleevegastrectomy procedures. Each of these procedures reconstructsgastrointestinal tract structure to create new features, by variouslycreating, for example, a gastric pouch, a stoma, such as a gastrojejunalstoma, or a gastric sleeve that restrict and/or divert the digestiveflow. These new or altered or reconstructed features of bariatricsurgery may also be generally referred to as bypass-reconstructedportion of a gastrointestinal tract.

In general, structures formed or altered by bariatric surgeries aresmaller or narrower than their natural predecessor structures; they thushold less food, and allow passage of food or chyme at a slower rate.Smaller or narrower structures are stressed and stretched, as thepatients habits and intake do not conform to the new physical realitiesof the gastrointestinal tract. Thus, in time, any portion of suchsurgically constructed features of a gastrointestinal tract may stretchor dilate, or lose its non-compliant quality, and in so doing, lose itseffectiveness in achieving or maintaining weight loss. The patient maythen regain excessive weight and be considered a surgical failure. Asdescribed herein however, ablation of portions of bypass-reconstructedfeatures can restore bariatric effectiveness.

Ablation, particularly well-controlled ablation, as provided herein, canhave any one or more of several effects that can restore or implementeffectiveness of the surgical anatomy in achieving additional weightloss, such as by stricturing or tightening of a lumen or stoma,diminishing compliance, or dampening peristaltic motility. Somebariatric procedures, such as a sleeve gastrectomy, form new structuresthat have an extended site of suturing or stapling that represent sitesof weakness or vulnerability. These sites, in particular, can benefitfrom therapeutic ablation that creates a healing or scarring responsethat tightens the treated area and prevents further stretching. Theseobjects of ablation in this therapeutic context are markedly differentthan the therapeutic objective, for example, of ablation in theesophagus to treat Barrett's esophagus. In that context, the object isto ablate a layer or population of cells that resides in the mucosallayer, but not to disturb the overall size or compliance of theesophagus, which would damage functionality of the organ and be harmfulto the patient. In the present therapeutic context, reduction of lumenvolume, and diminished stretchability of the luminal site is desirable.One embodiment or the method, for example, is to repeat ablationtreatments so as to create areas of overlap, such overlapping areashaving a particularly effective result in terms of creating luminalstricture and reducing the ability of the lumen to expand.Longitudinally overlapping treatment sites can creates undulating orcorrugated-like areas along the length of the surgically formed oraltered organ where stricture or non-compliant stiffness is particularlypronounced. The creation of such areas of particular striction andnon-compliance may provide overall benefit to the patient in terms ofachieving the desired weight-loss effect.

A number of embodiments of ablation devices are provided herein, whichmay be described as having an ablational surface that spans either a360-degree circumference, or some fractional portion of a fullcircumference around the device. For example, some devices have anablational surface that spans about 180 degrees, and others have anablational surface that spans about 90 degrees. The use of such ablationdevices to create ablational effects that are directed toward restoringor improving the effectiveness of bariatric surgical results will bedescribed in depicted below in detail.

FIGS. 1A-1D provide a view of a portion of a gastrointestinal tract thathas been reconstructed by either a Roux-en-Y bypass procedure (RGB) or abiliopancreatic diversion (BPD); the view includes the esophagus, thenproceeding distally, the gastroesophageal junction, a gastric pouch 7A,a stoma or anastomosis 8 between the gastric pouch and a portion of thesmall bowel, and a portion of the small bowel itself. In FIGS. 1A-1D and2A-2B, an ablation device of one of two types, 100A (with an ablationalsurface of 360 degrees) or 100B (with an ablational surface of less than360 degrees, such as the approximate 90 degree embodiment shown) issupported on an ablation catheter 41. The ablation device (100A or 100B)includes an ablation structure 101. In an embodiment where the ablationis RF-based, the ablation device typically includes an array ofelectrodes depicted in further detail in other figures, and an inflationmember or balloon 105.

FIG. 1A shows an ablative device 100A with a fully circumferentialoperating radius inserted into the gastric pouch, filling the lumen ofthe pouch. The ablative device is supported on the distal end of anelongated shaft 41 of an instrument, has been inserted into thealimentary tract by an oral or nasal entry route, and has been movedinto the proximity of an area targeted for treatment. FIG. 1A shows theablative device having entered the bypass-reconstructed gastrointestinaltract orally, having entered the gastric pouch 7A through the esophagus6. The device depicted is merely an exemplary illustration, andalternative devices are included as embodiments, however what theseembodiments have in common is an ablational surface that spans acomplete 360 degree circumference that is expandable through the use ofan expandable member included in the device internal to the ablationalsurface. Several such representative embodiments are shown and furtherdescribed below (FIGS. 6, 57, and 58) and described further below.Embodiments of the fully circumferential ablational surface aretypically cylindrical in form, but embodiments can includecircumferential ablational surfaces arranged on surfaces that departfrom strict cylindrical, and become more ovalular or spherical, as shownin FIGS. 58A and 58B, with one or both of the (proximal or distal) endsbeing tapered. By way of further description of the ablational surface,it includes ablational delivery elements such as non-penetratingradiofrequency electrodes, but other types of ablational energy elementsare includes as embodiments as well, and as described further below.Exemplary arrangements of radiofrequency electrodes are shown in FIG. 5,and 7-9. Arrangements of energy delivery elements that create afractional or partial ablation within a target area, as well as theablation patterns they deliver to target tissue, are described furtherbelow, and depicted in FIGS. 48-55. Another feature shared by energydelivery element patterns provided herein is that although the ablationpattern is on a surface that may be pressed into therapeutic contact byan expandable member, the immediate surface upon which the energydelivery elements are arranged is substantially non-distensible, thusthe density of elements across the surface remains constant.

FIG. 1B shows an ablative device 100B with a partially circumferentialoperating radius inserted into the gastric pouch 7A, and positionedagainst a portion of the wall. The device depicted is merely anexemplary illustration, and alternative devices are included asembodiments. Described below, and depicted in FIGS. 9-23, 26-47, and 56are a number of embodiments that provide an ablational surface of lessthan a fully circumferential span. In terms of the circumference withrespect to the device itself, some embodiments provide an ablationalsurface of about 90 degrees, some embodiments provide an ablationalsurface of about 180 degrees, however embodiments include anypartially-circumferential span. As described above in the context of thefully circumferentially-ablating device of FIG. 1A, ablational energyelements include radiofrequency electrodes, among others, and may bearranged on the surface in any pattern, including fractionally-ablatingpatterns. The radial portion of a bypass reconstructed gastrointestinallumen site (such as a gastric pouch 7A, a stoma 5, or a gastric sleeve7B) that can be ablationally treated in any single transmission ofradiant energy depends on the width of the electrode-covered ablationalsurface of the embodiment of the device, and the width or diameter ofthe luminal organ where the treatment site is located. The width ofembodiments of the ablational surface, in absolute terms, is describedin detail below. The arc of a curved treatment area can be anything lessthan 360 degrees, however it is typically less than 180 degrees, andmore particularly may include a smaller radial expanse such as arcs ofabout 5 degrees, about 10 degrees, about 15 degrees, about 30 degrees,about 45 degrees, about 60 degrees, and about 90 degrees.

FIG. 1C shows an ablative device 100A with a fully circumferentialoperating radius inserted into the stoma 5, filling the lumen of thestoma; and FIG. 1D shows an ablative device 100B with apartially-circumferential operating radius inserted into the stoma andpositioned against a portion of the stomal wall 5.

FIGS. 2A-2B provide a view of a portion of a gastrointestinal tract thathas been reconstructed by a sleeve gastrectomy. The esophagus andgastroesophageal junction are similar to that of the RGB or BPDprocedures as seen in FIGS. 1A-1C; the focus in FIGS. 2A and 2B,however, is on the gastric sleeve 7B formed by suturing or stapling atubular portion from the stomach, leaving sutured line or remnant 8,thereby removing the majority of the stomach from the digestive flowpath for. FIG. 2A shows an ablative device 100A with a fullycircumferential operating radius inserted into the gastric sleeve 7B,filling the lumen of the sleeve. FIG. 2B shows an ablative device 100Bwith a partially circumferential operating radius inserted into thegastric sleeve 7B, and positioned against a portion of the wall of thesleeve in the proximity of the remnant suture line 8. In the descriptionthat follows below, the label 100 may generally be used to designateablational devices, regardless of whether their ablational surface 101is fully circumferential or partially circumferential.

Metabolic conditions such as obesity, diabetes mellitus type 2, andmetabolic syndrome can become such a threat to the health of the patientthat medical intervention beyond diets and life-style recommendationsare indicated. One first line interventional approach is that ofbariatric surgery, while another first-line interventional, as describedin U.S. patent application Ser. No. 12/114,628 of Kelly et al., filedMay 2, 2008 is that of ablational therapy applied to specific sites inthe gastrointestinal tract. As noted above, in the background, however,the results of gastric bypass procedures include a significant level ofultimate failure mixed into a prevailing level of general success. Theapplicability of therapeutic methods (FIGS. 3 and 4) provided hereinrelates to patients in whom a bypass procedure has failed or becomeunsatisfactory with regard to its ability to manage body weight control.Accordingly, ablation may be included as a secondary form ofintervention in the event of bypass failure, such ablation beingdirected to specific sites within the surgically formed orsurgically-altered structures within the gastrointestinal tract.

Turning now to an aspect of therapeutic ablation methods providedherein, that of determining an appropriate site for ablational treatment(FIG. 3), as well as the amount of ablational energy to be appliedduring such treatment, such determinations follow from the total amountof clinical information that a clinician can gather on a particularpatient. In some aspects, the same clinical information that wasrelevant to the clinical status of a patient prior to bariatric bypasssurgery remains equally relevant when evaluating the appropriateness ofcorrective ablational therapy. Appropriate information to be evaluatedmay include, for example, the age of the patient, the basal metabolicindex, laboratory data on levels of metabolic hormones such as, merelyby way of example, any of insulin, glucagon, glucagon-like peptides,insulin-like growth factors, and ghrelin, as well as data on bloodglucose levels and glucose tolerance tests.

In some embodiments, a preliminary endoscopic examination of thefeatures of a bypass-reconstructed alimentary canal may be appropriateso that any patient-specific features may be mapped out, as well as anevaluation of the general dimensions of the patient's alimentary canal,particularly the newly formed bypass structures. Such information may beobtained by direct visual observation by endoscopic approaches withoptional use of mucosal in-situ staining agents, and may further beaccomplished by other diagnostic methods, including non-invasivepenetrative imaging approaches such as narrow band imaging from anendoscope. In one aspect, evaluation of a site includes identifying thelocale of the site, including its dimensions. In another aspect,evaluation of target tissue includes identifying a multiplicity ofsites, if there is more than one site, and further identifying theirlocale and their respective dimensions. In still another aspect,evaluating target sites may include identifying or grading any pathologyor injury or specific site of failure within the bypass-reconstructedgastrointestinal tract, particularly identifying any areas of clinicalsignificance or concern that are overlapping or near the areas to betargeted for ablation. Typically, features of a gastrointestinal tractthat has been subjected to bariatric surgery, and which has subsequentlybeen found to be functionally unsuccessful in terms of the patientachieving loss of excess weight, will be dilated or distended, and showsigns of being overly compliant, i.e., too easily stretched.

Once target sites for ablation have been identified,bypass-reconstructed gastrointestinal target tissue may be treated withembodiments of an inventive ablational device and associated methods asdescribed herein. Evaluation of the status of target tissue sites forablation, particularly by visualization approaches, may also beadvantageously implemented as part of an ablational therapy method (FIG.3), as for example, in close concert with the ablation, eitherimmediately before the application of ablational energy (such as radiantenergy), and/or immediately thereafter. Further, the treatment site canbe evaluated by any diagnostic or visual method at some clinicallyappropriate time after the ablation treatment, as for example a fewdays, several weeks, or several few months, or at anytime whenclinically indicated following ablational therapy. In the event that anyfollow-up evaluation shows either that the therapy was unsatisfactorilycomplete, or that there is a recovery in the population of cellstargeted for ablation, a repetition of the ablational therapy may beindicated.

Turning now to aspects of ablational devices that can be directed towardablational correction of failed bypass procedures, as described indetail herein, ablational devices have an ablational structure arrayedwith energy-transmitting elements such as electrodes. In someembodiments, depending on the type of ablatative energy being used inthe therapy, the devices may be mounted on, or supported by anyappropriate instrument that allows movement of the ablational surface tothe local of a target site. Such instruments are adapted in form anddimension to be appropriate for reaching the target tissue site, and mayinclude simple catheters adapted for the purpose; some embodiments ofthe insertive instrument include endoscopes that, in addition to theirsupportive role, also provide a visualization capability. In someembodiments of the method, an endoscope separate from the supportiveinstrument may participate in the ablational procedure by providingvisual information.

Exemplary embodiments of the inventive device as described hereintypically make use of electrodes to transmit radiofrequency energy, butthis form of energy transmission is non-limiting, as other forms ofenergy, and other forms of energy-transmission hardware are included asembodiments of the invention. Ablational energy, as provided byembodiments of the invention, may include, by way of example, microwaveenergy emanating from an antenna, light energy emanating from photonicelements, thermal energy transmitted conductively from heated ablationalstructure surfaces or as conveyed directly to tissue by heated gas orliquid, or a heat-sink draw of energy, as provided by cryonic orcryogenic cooling of ablational structure surfaces, or as applied bydirect contact of cold gas or fluid with tissue, or by heat-draw througha wall of a device that separates the cold gas or fluid from the tissue.

Embodiments of the ablational device include variations with regard tothe circumferential expanse of the ablational surface to be treated,some embodiments provide a fully circumferential ablation surface andothers provide a surface that is less than fully circumferential, asdescribed above. Choosing the appropriate device is a step includedwithin the therapeutic method provided, as shown in FIG. 3. These andother variation may provide particular advantages depending on thenature, extent, locale, and dimensions of the one or more targetedtissue sites on the wall the alimentary canal. One embodiment of theinvention includes a device with an ablational surface that is fullycircumferential, i.e., encompassing a radius of 360 degrees, such that afull radial zone within a luminal organ is subject to ablation. Withinthat zone, ablation may be implemented to a varying degree, depending onthe energy output and the pattern of the ablational elements (such aselectrodes), but with substantial uniformity within the zone ofablation. This embodiment may be particularly appropriate for treatingwidespread or diffuse sites within a bypass-reconstructedgastrointestinal tract organ. In another embodiment of the device, theablational surface of the inventive device is partially circumferential,such that it engages a fraction of the full internal perimeter orcircumference of a luminal organ. The fractional portion of thecircumference ablated on the inner surface of a luminal organ depends onthe size of the luminal organ being treated (radius, diameter, orcircumference) and on the dimensions of the ablational surface, asdetailed further below. With regard to treating target sites that aresmall and discrete, the smaller or more discrete ablational surfaceprovided by this latter embodiment may be advantageous.

This type of operational control of a circumferential subset of ablationenergy elements around a 360-degree circumferential array is analogousto the fractional operation of a patterned subset of an electrode array,as described below in the section titled “Electrode patterns and controlof ablation patterns across the surface area of tissue”. In thepartially-circumferential operation of an array, a particular arc of thearray is activated to deliver energy to an arc of the circumference. Inthe fractional-pattern operation of an array, energy is delivery to aportion of the tissue in the target area, while another portion receivesinsufficient energy to achieve ablation. In some embodiments, theseoperational variations can be combined, that is, a patterned subset of acircumferential arc can be activated.

FIGS. 3 and 4 together provide flow diagram depictions of embodiments ofthe method for ablating tissue in the wall of the alimentary canal thathas been reconstructed by a bariatric procedure, and has subsequentlyfailed or been demonstrably ineffective. The diagrams represent commonaspects of the embodiments of the method, as delivered by twoembodiments of the device, one which has a 360 degree circumferentialablation structure, and one which has an ablation structure comprisingan arc of less than 360 degrees.

FIG. 3 is a flow diagram depicting an overview of the method with afocus on patient evaluation and determination of a clinicallyappropriate site within the alimentary canal for ablational treatment.In another step, a responsible clinician makes an informed choice withregard to the appropriate embodiment with which to treat the patient,i.e., either a device with the 360 degree electrode array 10A, or adevice 100B with the electrodes arrayed in an arc of less than 360degrees. In the event that the device 100A is chosen for use, anothertreatment choice may be made between operating the electrodes throughoutthe 360 degree circumference, or whether to operate a radial subset ofthe electrode array. In another step, a clinician further considers andmakes a determination as to the protocol for ablation, considering theamount of energy to be delivered, the energy density, the duration oftime over which energy is to be delivered. These considerations takeinto the account the surface area to be ablated, the depth of tissuewhich is to be treated, and the features of the electrode array,whether, for example, it is to be a fractional electrode, and whichpattern may be desirable. Regardless of the device chosen, anotherpreliminary step to operating the method may include a closer evaluationof the target tissue site(s) within the alimentary canal. Evaluation ofthe site may include the performance of any visualization or diagnosticmethod that provides a detailed census of the number of discrete targettissue sites, their dimensions, their precise locations, and/or theirclinical status, whether apparently normal or abnormal. This step isshown following the choice of instrument, but may occur simply inconjunction with diagnosis, or at any point after diagnosis and generallocalization of the target tissue. In any case, an evaluating step istypically performed prior to ablation, as outlined in the operationalsteps of the method, as shown in the flow diagram of FIG. 4.

FIG. 4 is a flow diagram depicting the method after the target sitewithin the bypass-reconstructed gastrointestinal tract has beenlocalized and a choice has been made regarding the preferred ablationaldevice. The method includes an evaluation of the site, includingparticulars of location, stage, determination of the number of sites,and the dimensions, as described above, and using approaches detailed inthe references provided in the background, and/or by using whateverfurther approaches may be known by those practiced in the art. Themethod continues with insertion of the instrument and the movement ofthe ablational structure to the locale of the target tissue to beablated. Subsequently, more refined movements of the ablationalstructure may be performed that create a therapeutically effectivecontact between the ablational structure and the target tissue site. Inthe event that the 360 degree embodiment of the device 100A is chosen,therapeutically effective contact may be made by inflating a balloonunderlying the electrode array. In the event that the embodiment chosenis 100B, the device with an electrode surface spanning an arc of lessthan 360 degrees, movements that bring the ablational surface intotherapeutically effective contact may include any of inflation of aballoon, inflation of a deflection member, and/or movement of adeflection member, all of which are described further below.

After therapeutically-effective contact is made, by either deviceembodiment 100A or 100B, and by whatever type of movement was that wastaken, a subsequent step includes the emission of ablational energy fromthe device. Variations of ablational energy emission may includeablating a single site as well as moving the instrument to a second orto subsequent sites that were identified during the evaluation step.Following the ablational event, a subsequent step may include anevaluation of the treated target site; alternatively evaluation of theconsequences of ablation may include the gathering of clinical data andobservation of the patient. In the event that an endoscope is includedin the procedure, either as the instrument supporting the ablationalstructure, or as a separate instrument, such evaluation may occurimmediately or very soon after ablation, during the procedure, wheninstruments are already in place. In other embodiments of the method,the treated site may be evaluated at any clinically appropriate timeafter the procedure, as for example the following day, or the followingweek, or many months thereafter. In the event that any of theseevaluations show an ablation that was only partially complete, or showan undesired repopulation of targeted cells, the method appropriatelyincludes a repetition of the steps just described and schematicallydepicted in FIG. 4.

In addition to observation by direct visual approaches, or otherdiagnostic approaches of site of ablation per se, evaluation of theconsequences of ablation may include the gathering of a completespectrum of clinical and metabolic data from the patient. Suchinformation includes any test that delivers information relevant to themetabolic status of the patient such as the information gathered whendetermining the appropriateness of ablational intervention, as was madein the first step of FIG. 3. Similarly, evaluation of the effectivenessof the bariatric effectiveness of the ablation method may include any ofa panoply of metabolic tests such as described in detail in U.S. patentapplication Ser. No. 12/114,628 of Kelly et al. entitled “Method andapparatus for gastrointestinal tract ablation for treatment of obesity”,as filed on filed May 2, 2008.

Device and Method for 360 Degree Circumferential Ablation

Methods for accomplishing ablation of targeted cells within thebypass-reconstructed gastrointestinal tract according to this inventioninclude the emission of radiant energy at conventional levels toaccomplish ablation of epithelial and with or without deeper levels oftissue injury, more particularly to remove or functionally compromisecells that are involved in the sensation of satiety or the regulation ofmetabolic hormones such as insulin. In one embodiment, as shown in FIGS.1A, 1C, and 2A, an elongated flexible shaft 41 is provided for insertioninto the body in any of various ways selected by a medical careprovider. The shaft may be placed endoscopically, e.g. passing throughthe mouth and esophagus and then further into the bypass-reconstructedgastrointestinal tract, or it may be placed surgically, or by any othersuitable approach. In this embodiment, radiant energy distributionelements or electrodes on an ablation structure 101 are provided at adistal end of the flexible shaft 41 to provide appropriate energy forablation as desired. In typical embodiments described in this section,the radiant energy distribution elements are configuredcircumferentially around 360 degrees. Alternatively to using emission ofRF energy from the ablation structure, alternative energy sources can beused with the ablation structure to achieve tissue ablation and may notrequire electrodes. Such energy sources include: ultraviolet light,microwave energy, ultrasound energy, thermal energy transmitted from aheated fluid medium, thermal energy transmitted from heated element(s),heated gas such as steam heating the ablation structure or directlyheating the tissue through steam-tissue contact, light energy eithercollimated or non-collimated, cryogenic energy transmitted by cooledfluid or gas in or about the ablation structure or directly cooling thetissue through cryogenic fluid/gas-tissue contact. Embodiments of thesystem and method that make use of these aforementioned forms ofablational energy include modifications such that structures, controlsystems, power supply systems, and all other ancillary supportivesystems and methods are appropriate for the type of ablational energybeing delivered.

In some embodiments of a fully circumferential ablation device, theflexible shaft comprises a cable surrounded by an electrical insulationlayer and comprises a radiant energy distribution elements located atits distal end. In one form of the invention, a positioning anddistending device around the distal end of the instrument is ofsufficient size to contact and expand the walls of thebypass-reconstructed gastrointestinal tract lumen or organ in which itis placed (e.g. the gastric pouch, the stoma, or the gastric sleeve)both in the front of the energy distribution elements as well as on thesides of the energy distribution elements. For example, the distal headof the instrument can be supported at a controlled distance from thewall of the bypass-reconstructed gastrointestinal tract lumen or organby an expandable balloon or inflation member, such that atherapeutically-effective contact is made between the ablation structureand the target site so as to allow regulation and control the amount ofenergy transferred to the target tissue within the lumen when energy isapplied through the electrodes. The balloon is preferably bonded to aportion of the flexible shaft at a point spaced from the distal headelements.

Some embodiments of a fully-circumferential ablation device include adistendible or expandable balloon member as the vehicle to deliver theablation energy. One feature of this embodiment includes means by whichthe energy is transferred from the distal head portion of the inventionto the membrane comprising the balloon member. For example, one type ofenergy distribution that may be appropriate and is incorporated hereinin its entirety is shown in U.S. Pat. No. 5,713,942, in which anexpandable balloon is connected to a power source that provides radiofrequency power having the desired characteristics to selectively heatthe target tissue to a desired temperature. A balloon per embodiments ofthe current invention may be constructed of an electroconductiveelastomer such as a mixture of polymer, elastomer, and electroconductiveparticles, or it may comprise a nonextensible bladder having a shape anda size in its fully expanded form which will extend in an appropriateway to the tissue to be contacted. In another embodiment, anelectroconductive member may be formed from an electroconductiveelastomer wherein an electroconductive material such as copper isdeposited onto a surface and an electrode pattern is etched into thematerial and then the electroconductive member is attached to the outersurface of the balloon member. In one embodiment, the electroconductivemember, e.g. the balloon member 105, has a configuration expandable inthe shape to conform to the dimensions of the expanded (not collapsed)inner lumen of the human lower bypass-reconstructed gastrointestinaltract. In addition, such electroconductive member may consist of aplurality of electrode segments arrayed on an ablation structure 101having one or more thermistor elements associated with each electrodesegment by which the temperature from each of a plurality of segments ismonitored and controlled by feedback arrangement. In another embodiment,it is possible that the electroconductive member may have means forpermitting transmission of microwave energy to the ablation site. In yetanother embodiment, the distending or expandable balloon member may havemeans for carrying or transmitting a heatable fluid within one or moreportions of the member so that the thermal energy of the heatable fluidmay be used as the ablation energy source.

Some embodiments of a fully circumferential ablation device include asteerable and directional control means, a means for accurately sensingdepth of cautery, and appropriate alternate embodiments so that in theevent of a desire not to place the electroconductive elements within themembrane forming the expandable balloon member it is still possible toutilize the balloon member for placement and location control whilemaintaining the energy discharge means at a location within the volumeof the expanded balloon member, such as at a distal energy distributionhead.

Embodiments of the invention include methods whereby an ablation device,such as a fully circumferential ablation device, is used as a method ofrestoring or rescuing the therapeutic effectiveness of bariatricprocedures that have failed or are degrading due to a compromise orunsatisfactory result in a surgically formed gastrointestinal tractfeature. In one aspect, the surgery can be understood as an initialtherapy that has failed, and the ablation can be understood as asecondary interventional therapy. As such, the primary indicationremains, i.e., the metabolic disease, but the ablational therapy isbeing directed more immediately toward supporting the initial surgicalintervention. Ablational targets, thus include structures such as agastric pouch, stomas formed by the procedure, or gastric tubes orsleeves. After determining that the portion or portions of thebypass-reconstructed gastrointestinal tract wall having this tissue thatis targeted either for full or partial ablation, the patient is preparedfor a procedure in a manner appropriate according to the embodiment ofthe device to be utilized. Then, the practitioner inserts into thepatient, in one embodiment, the ablation device shown and discussedherein via endoscopic access and control. Further positioning ofportions of the device occurs as proper location and visualizationidentifies the ablation site in the bypass-reconstructedgastrointestinal tract. Selection and activation of the appropriatequadrant(s) or portion(s)/segment(s) on the ablation catheter member isperformed by the physician, including appropriate power settingsaccording to the depth of cautery desired. Additional settings may benecessary as further ablation is required at different locations and/orat different depths within the patient's bypass-reconstructedgastrointestinal tract. Following the ablation, appropriate follow-upprocedures as are known in the field are accomplished with the patientduring and after removal of the device from the bypass-reconstructedgastrointestinal tract.

In yet another method of the invention, the practitioner may firstdetermine the length of the portion of the bypass-reconstructedgastrointestinal tract requiring ablation and then may choose anablation catheter from a plurality of ablation catheters of theinvention, each catheter having a different length of the electrodemember associated with the balloon member. For example, if thepractitioner determines that 1 centimeter of the bypass-reconstructedgastrointestinal tract surface required ablation, an ablation catheterhaving 1 centimeter of the electrode member can be chosen for use in theablation. The length of the electrode member associated with the balloonmember can vary in length, as for example, from 1 to 10 cm.

In yet another embodiment, a plurality of ablation catheters wherein theradiant energy distribution elements are associated with the balloonmember can be provided wherein the diameter of the balloon member whenexpanded varies from 12 mm to 40 mm. In this method, the practitionerwill choose an ablation catheter having a diameter when expanded whichwill cause the bypass-reconstructed gastrointestinal tract to stretchand the mucosal layer to thin out, thus, reducing or occluding bloodflow at the site of the ablation. It is believed that by reducing theblood flow in the area of ablation, the heat generated by the radiantenergy is less easily dispersed to other areas of the target tissue thusfocusing the energy to the ablation site.

One approach a practitioner may use to determine the appropriatediameter ablation catheter to use with a particular patient is to use ina first step a highly compliant balloon connected to a pressure sensingmechanism. The balloon may be inserted into a luminal organ within thebypass-reconstructed gastrointestinal tract and positioned at thedesired site of the ablation and inflated until an appropriate pressurereading is obtained. The diameter of the inflated balloon may bedetermined and an ablation device of the invention having a balloonmember capable of expanding to that diameter chosen for use in thetreatment. In the method of this invention, it is desirable to expandthe expandable electroconductive member such as a balloon sufficientlyto occlude the vasculature of the submucosa, including the arterial,capillary or venular vessels. The pressure to be exerted to do so shouldtherefore be greater than the pressure exerted by such vessels.

In other embodiments of the method, electronic means are used formeasuring the luminal target area of gastrointestinal features that havebeen formed by bariatric surgery so that energy may be appropriatelynormalized for the surface area of the target tissue. These aspects ofthe method are described in detail in U.S. patent application Ser. No.12/143,404, of Wallace et al., entitled “Electical means to normalizeablational energy transmission to a luminal tissue surface of varyingsize”, as filed on Jun. 20, 2008, which is incorporated in entirety. Anembodiment of a device with a 360 degree ablational surface is describedin detail in that application, and is depicted in FIGS. 57A-57D of thisapplication. Pressure sensing means may also be used to measure the sizeof a lumen in preparation for an ablation treatment, as described inU.S. patent application Ser. No. 11/244,385 of Jackson, published asU.S. 2006/0095032.

An embodiment of a device disclosed in U.S. patent application Ser. No.12/143,404, of Wallace et al will be described here briefly, in order toprovide an embodiment that includes a 360-degree ablational surfacearranged on an overlapping support that expands in accordance with aballoon enclosed within the circumference of the support. Although thecircumference of the device as a whole expands with the balloon, theablational surface itself is non-distensible, and maintains itselectrode density. FIGS. 57A-57D provide perspective views of anablation device 100 with an overlapping electrode support 360 furledaround an expandable balloon 105. An array of ablational energy deliveryelements 101 such as radiofrequency electrodes is arranged on theexterior surface of the electrode support. The operative element ismounted on the distal end of an ablation catheter, of which the distalportion of a shaft 41 is seen, and around which the balloon 105 isconfigured. FIG. 57A shows the electrode support 360 pulled away fromthe balloon 105 to clarify that a portion of the support and an inneredge 362 is adherent to the balloon, and another portion and its outeredge 364 is not connected to the balloon. FIG. 57B shows thenon-adherent portion of the electrode support 360 furled around theballoon 105 in a deployable configuration, the non-adherent portion andits edge overlapping around the adherent portion. FIG. 57C shows anoptional feature of the device 10A, one or more elastic bands 380wrapped around the electrode support 360. In some embodiments, theelastic band 380 material is a conductive elastomer, as described ingreater detail below, which can be included in a size-sensing circuit toprovide information related to the degree of expansion of the operativeelement. FIG. 57D shows the device of FIG. 57C in a collapsed state,with balloon portion 105 being uninflated (or deflated), this being thestate of the device when it is being deployed into a lumen and beingpositioned at a target site, as well as the state of the device afterdelivering ablation energy and about to be removed from the lumen.

Another embodiment of an ablation device with a fully circumferentialablation surface is provided in FIGS. 58A-58B. This particular deviceembodiment 400 is adapted to present an ablational surface 101 into aconcave or inwardly tapered target site such as distal portion of theantrum of the stomach, or in the vicinity of the pylorus, which is asite for vascular lesions typical of watermelon stomach. The deviceincludes an ablational surface circumferentially arranged on the distalportion of an expandable member 105, the expandable member mountedaround the distal end 110 of the shaft of an endoscope 111. FIG. 58Ashows the device in a deployed configuration. FIG. 58B shows the devicewith the expandable member in an unexpanded or collapsed state, as wouldbe appropriate for deployment of the device to a target tapered surface,or as would be appropriate for removal from the ablational site. FIG.58C shows the device of FIG. 58A as it can be deployed into a tapered orconcave target site such as the pylorus 9. FIG. 58D shows the device ofFIG. 58A in an alternative configuration, with the electrode bearingsurface of the device reversed such that it is facing proximally, andcan thus be pulled retrograde into a tapered or concave site such as thelower esophageal sphincter 10.

Electrode Patterns and Control of Ablation Patterns Across the SurfaceArea of Tissue

Some aspects of embodiments of the ablational device and methods of usewill now be described with particular attention to the electrodepatterns present on the ablation structure. The device used is shownschematically in FIGS. 5-7. As shown in FIG. 6, the elongated flexibleshaft 41 of a device with a fully circumferential ablation surface isconnected to a multi-pin electrical connector 94 which is connected tothe power source and includes a male luer connector 96 for attachment toa fluid source useful in expanding the expandable member. The elongatedflexible shaft has an electrode 98 wrapped around the circumference. Theexpandable member of the device shown in FIGS. 5 and 6 further includesthree different electrode patterns, the patterns of which arerepresented in greater detail in FIGS. 7A-7C. Typically, only oneelectrode pattern is used in a device of this invention, although morethan one may be included. In the device shown in FIG. 5, the elongatedflexible shaft 41 comprises six bipolar rings 62 with about 2 mmseparation at one end of the shaft (one electrode pattern), adjacent tothe bipolar rings is a section of six monopolar bands or rectangles 65with about 1 mm separation (a second electrode pattern), and anotherpattern of bipolar axial interlaced finger electrodes 68 is positionedat the other end of the shaft (a third electrode pattern). In thisdevice, a null space 70 is positioned between the last of the monopolarbands and the bipolar axial electrodes. The catheter used in the studywas prepared using a polyimide flat sheet of about 1 mil (0.001″)thickness coated with copper. The desired electrode patterns were thenetched into the copper.

Alternative electrode patterns are shown in FIGS. 8A-8D as 80, 84, 88,and 92, respectively. Pattern 80 is a pattern of bipolar axialinterlaced finger electrodes with about 0.3 mm separation. Pattern 84includes monopolar bands with 0.3 mm separation. Pattern 88 is that ofelectrodes in a pattern of undulating electrodes with about 0.25 mmseparation. Pattern 92 includes bipolar rings with about 0.3 mmseparation. In this case the electrodes are attached to the outsidesurface of a balloon 72 having a diameter of about 18 mm. The device maybe adapted to use radio frequency by attaching wires 74 as shown in FIG.5 to the electrodes to connect them to the power source.

The preceding electrode array configurations are described in thecontext of an ablation structure with a full 360 degree ablationsurface, but such patterns or variants thereof may also be adapted forablation structures that provide energy delivery across a surface thatis less than completely circumferential, in structures, for example,that ablate over any portion of a circumference that is less than 360degrees, or for example structures that ablate around a radius of about90 degrees, or about 180 degrees.

Embodiments of the ablation system provided herein are generallycharacterized as having an electrode pattern that is substantially flaton the surface of an ablation support structure and which isnon-penetrating of the tissue that it ablates. The electrode patternforms a contiguous treatment area that comprises some substantial radialaspect of a luminal organ; this area is distinguished from ablationalpatterns left by electrical filaments, filament sprays, or single wires.In some embodiments of the invention the radial portion may be fullycircumferential; the radial portion of a luminal organ that is ablatedby embodiments of the invention is function of the combination of (1)the circumference of the organ, which can be relatively large in thecase of gastric pouch, and small when in the case of a region in a stomaor a gastric sleeve, and (2) the dimensions of the electrode pattern.Thus, at the high end, as noted, the radial expanse of a treatment areamay be as large as 360 degrees, and as small as about 5 to 10 degrees,as could be the case in a treatment area within the stomach.

Embodiments of the ablational energy delivery system and method providedare also characterized by being non-penetrating of the target tissue.Ablational radiofrequency energy is delivered from the flat electrodepattern as it makes therapeutic contact with the tissue surface of atreatment area, as described elsewhere in this application; and fromthis point of surface contact, energy is directly inwardly to underlyingtissue layers.

Some embodiments of the ablational system and method provided herein canbe further characterized by the electrode pattern being configured toachieve a partial or fractional ablations, such that only a portion ofthe tissue surface receives sufficient radiofrequency energy to achieveablation and another portion of the surfaces receives insufficientenergy to achieve ablation. The system and method can be furtherconfigured to control the delivery of radiofrequency energy inwardlyfrom the tissue surface such that depth of tissue layers to which energysufficient for ablation is delivered is controlled.

Controlling the fraction of the tissue surface target area that isablated comes about by having some fraction of the tissue ablated, atleast to some degree, and having some fraction of the surface within thetarget area emerge from the treatment substantially free of ablation.The ability to control the ratio of ablated and non-ablated surface canprovide substantial benefit to the treatment. The ablational targetareas in this method, after all, are not cancerous, in which case theircomplete ablation may be desired, and in fact the target areas may notbe abnormal in any sense. The ablational treatment, per embodiments ofthis invention, may directed not necessarily toward correcting anydefect of the target tissue, but rather toward a larger therapeutic end,where, in fact, that end is served by creation of a modulated dampeningof the normal properties or function of the target area. It may not bethe case, for example, when treating a compromised feature of agastrointestinal tract reconfigured by a bariatric surgery, or anunderlying metabolic condition such as obesity or diabetes, that it isdesirable to render a complete ablation, it may be that what is desiredis a modulated approach, where a varying degree of dysfunction can beprovided, without substantially damaging the organ, or a particularlayer of the organ. Stated in another way, it may be generally desirablefor the health of the organ within which the target area is located, andfor the health of the individual as a whole, that some degree of normalfunctioning remain after ablation.

By way of an illustrative example as to what is desirable and beingprovided by the invention, the organ in which the ablation target areais located can be appreciated as a population of particular target cellswithin the tissue of the target area, which can function, based on theirhealth, at a functional capacity at some low threshold of 20%, forexample, when in poor condition, and at 100%, when in optimal condition.The object of the ablational treatment provided herein, within thisexample by analogy may not be to render the full population of cells tobe dysfunctional and operating at 50% capacity. The object of thetreatment may be to have some fraction of the cells within thepopulation, post-ablational treatment, to remain fully functional,operating at about 100% capacity, and to have some remaining fractionoperating at a range of lower capacity.

Controlling the fraction of the tissue surface target area that isablated, per embodiments of the invention, is provided by variousexemplary approaches: for example, by (1) the physical configuration ofelectrode pattern spacing in a comparatively non-dense electrodepattern, and by (2) the fractional operation of a comparatively denseelectrode array, in a billboard-like manner. Generally, creating afractional ablation by physical configuration of the electrode patternincludes configuring the electrode pattern such that some of the spacingbetween electrodes is sufficiently close that the conveyance of a givenlevel of energy between the electrodes sufficient to ablate tissue isallowed, and other spacing between electrodes is not sufficiently closeenough to allow conveyance of the level of energy sufficient to ablate.Embodiments of exemplary electrode patterns that illustrate thisapproach to creating fractional ablation are described below, anddepicted in FIGS. 48-55. The creation of an ablation pattern byactivating a subset of electrodes represents an operation of theinventive system and method which is similar to the described above,wherein an ablational structure with a fully circumferential pattern ofelectrodes can be operated in a manner such that only a radial fractionof the electrodes are operated.

The ablation system of the invention includes an electrode pattern witha plurality of electrodes and a longitudinal support member supportingthe electrode pattern, as described in numerous embodiments herein.Energy is delivered to the electrodes from a generator, and theoperation of the generator is controlled by a computer-controller incommunication with the generator, the computer controller controllingthe operating parameters of the electrodes. The computer controller hasthe capability of directing the generator to deliver energy to all theelectrodes or to a subset of the electrodes. The controller further hasthe ability to control the timing of energy delivery such thatelectrodes may be activated simultaneously, or in subsets,non-simultaneously. Further, as described elsewhere, the electrodes maybe operated in a monopolar mode, in a bipolar mode, or in a multiplexingmode. These various operating approaches, particularly by way ofactivating subsets of electrodes within patterns, allow the formation ofpatterns that, when the pattern is in therapeutic contact with a targetsurface, can ablate a portion of tissue in the target area, and leave aportion of the tissue in the target area non-ablated.

Generally, creating a fractional ablation by an operational approachwith a comparatively dense electrode array includes operating theelectrode pattern such that the energy delivered between some of theelectrodes is sufficient to ablate, whereas energy sufficient to ablateis not delivered between some of the electrodes. Embodiments ofexemplary electrode patterns that illustrate this approach to creatingfractional ablation are described below, and depicted in FIGS. 48-55.

Another aspect of controlling the fraction of tissue ablation, perembodiments of the invention, relates to controlling the depth ofablation into tissue layers within the target area. Energy is deliveredinwardly from the surface, thus with modulated increases in energydelivery, the level of ablation can be controlled such that, forexample, the ablated tissue may consist only of tissue in the epitheliallayer, or it may consist of tissue in the epithelial layer and thelamina propria layers, or it may consist of tissue in the epithelial,lamina propria and muscularis mucosal layers, or it may consist oftissue in the epithelial, lamina propria, muscularis mucosa, andsubmucosal layers, or it may consist of tissue in the epithelial layer,the lamina propria, the muscularis mucosae, the submucosa, and themuscularis propria layers. Typically, ablational energy not delivered tothe serosal layer of the bypass-reconstructed gastrointestinal tract.

Embodiments of the invention include RF electrode array patterns thatablate a fraction of tissue within a given single ablational area,exemplary fractional arrays are shown in FIGS. 48A, 49A, and 50A. Thesefractional ablation electrode arrays may be applied, as above, to aboveto ablational structures that address a fully circumferential targetarea, or a structure that addresses any portion of a full circumferencesuch as 90 degree radial surface, or a 180 degree radial surface. FIG.48A shows a pattern 180 of linear electrodes 60 aligned in parallel asstripes on a support surface. The electrodes are spaced apartsufficiently such that when pressed against tissue in therapeuticcontact, the burn left by distribution of energy through the electrodesresults in a striped pattern 190 on the target tissue as seen in FIG.48B corresponding to the electrode pattern, with there being stripes ofburned or ablated tissue 3 a that alternate with stripes of unburned, orsubstantially unaffected tissue 3 b. In some embodiments of the method,particularly in ablation structures that address a target area of lessthan 360 radial degrees, such as a target surface that is about 180degrees, or more particularly about 90 degrees of the innercircumference of a lumen, the ablation may be repeated with theablational structure positioned at a different angle. FIG. 48C, forexample, depicts a tissue burn pattern 191 created by a first ablationalevent followed by a second ablational event after the ablationalstructure is laterally rotated by about 90 degrees. FIG. 48D, foranother example, depicts a tissue burn pattern 192 created by a firstablational event followed by a second ablational event after theablational structure is laterally rotated by about 45 degrees.

The effect of an ability to ablate a tissue surface in this manner addsanother level of fine control over tissue ablation, beyond suchparameters as total energy distributed, and depth of tissue ablation.The level of control provided by fractional ablation, and especiallywhen coupled with repeat ablational events as described above in FIGS.48C and 48D, is to modulate the surface area-distributed fraction oftissue that is ablated to whatever degree the local maximal ablationlevel may be. The fractional ablation provided by such fractionalelectrode pattern may be particularly advantageous when the effects ofablation are not intended to be absolute or complete, but instead afunctional compromise of tissue, or of cells within the tissue isdesired. In some therapeutic examples, thus, a desirable result could bea partial reduction in overall function of a target area, rather than atotal loss of overall function. Another example where such fractionalablation may be desirable is in the case where ablation is intended tobe temporary or transient. In a fractional ablation of a target area inthe wall of a bypass-reconstructed gastrointestinal lumen, for example,a desirable result may be the transient compromise of tissue duringwhich time the effect of such compromise may be evaluated. In anablation pattern that includes a burned area 3 a and an unburned area 3b, it can be understood that cells from the unburned area could giverise to cells that would migrate or repopulate the denuded area withinthe burned area 3 b.

FIGS. 49A and 50A depict other examples of a fractionally-ablatingelectrode pattern on an ablation structure, and FIGS. 49B and 50B showthe respective fractional burn patterns on tissue that have been treatedwith these electrode patterns. In FIG. 49A a pattern of concentriccircles 182 is formed by wire electrodes that (from the center andmoving outward) form a + − − + + − pattern. When activated, the tissuebetween + − electrodes is burned, and the tissue between ++ electrodepairs or − − electrode pairs is not burned. Thus, the concentric pattern192 of FIG. 49B is formed. Embodiments of fractionally-ablatingelectrode patterns such as those in FIG. 49A need not include perfectcircles, and the circles (imperfect circles or ovals) need not beperfectly concentric around a common center.

Similarly, FIG. 50A shows a checkerboard pattern 184 of + and −electrodes which when activated create a burn pattern 194 as seen inFIG. 50B. Tissue that lies between adjacent + and − electrodes isburned, while tissue that lies between adjacent + + electrodes or − −electrode pairs remains unburned. FIG. 50B includes a representation ofthe location of the + and − electrodes from the ablation structure inorder to clarify the relative positions of areas that are burned 3 a andthe areas that remain substantially unburned 3 b.

Embodiments of the invention include RF electrode array patterns thatablate a fraction of tissue within a given single ablational area byvirtue of operational approaches, whereby some electrodes of a patternare activated, and some are not, during an ablational event visited upona target area. Exemplary fractional arrays are shown in FIGS. 51A, 52A,53A and 54A. These fractional ablation electrode arrays may be applied,as above, to ablational structures that address a fully circumferentialtarget area, or a structure that addresses any portion of a fullcircumference such as, by way of example, a 90 degree radial surface, ora 180 degree radial surface.

FIG. 51A shows a checkerboard electrode pattern during an ablationalevent during which all electrode squares of the operational pattern 186Aare operating, as depicted by the sparkle lines surrounding eachelectrode. Operating the electrode pattern 186A in this manner producesan ablation pattern 196A, as seen in FIG. 51B, wherein the entiresurface of tissue within the treatment area is ablated tissue 3 a. FIG.52A, on the other hand, shows a checkerboard electrode pattern during anablational event during which only every-other electrode square of theoperational pattern 186B is operating, as depicted by the sparkle linessurrounding each activated electrode. Operating the electrode pattern186B in this manner produces an ablation pattern 196B, as seen in FIG.52B, wherein a checkerboard fractionally ablated pattern with adispersed pattern of ablated squares 3 a of tissue 3 a alternate withsquare areas of tissue 3 b that are not ablated.

FIG. 53A shows a striped linear electrode pattern of alternating + and −electrodes during an ablational event during which all electrode squaresof the operational pattern 188A are operating, as depicted by thesparkle lines surrounding each linear electrode. Operating the electrodepattern in this manner 188A produces an ablation pattern 198A, as seenin FIG. 53B, wherein the entire surface of tissue within the treatmentarea is ablated tissue 3 a.

FIG. 54A, on the other hand, shows a striped linear electrode pattern188B of alternating + and − electrodes during an ablational event duringwhich alternate pairs of the linear electrode pairs are operating, asdepicted by the sparkle lines surrounding the activated linearelectrodes. Operating the electrode pattern in this manner 188B producesan ablation pattern 198B, as seen in FIG. 54B, wherein stripes ofablated tissue 3 a within the treatment area alternate stripes ofnon-ablated tissue 3 b.

FIG. 55 is a schematic rendering of a three dimensional view of a targetregion of a radial portion of a bypass-reconstructed gastrointestinalwall after it has been ablationally treated, per embodiments of theinvention. Ablated regions 3 a are rendered as regions distributedthrough the target area within a larger sea of non-ablated tissue 3 b.These regions are depicted as being slightly conical in this schematicview, but in practice the ablated tissue region may be more cylindricalin shape. The regions 3 a are of approximately the same depth, becauseof the control exerted over the depth of the ablation area into layersof the gastrointestinal wall, as described herein. With such control,the regions 3 a can vary with respect of the layer to which they extendcontinuously from the upper surface where ablational energy has beenapplied. The conical regions are of approximately the same width ordiameter, and distributed evenly throughout the tissue, because of thecontrol over ablational surface area, as described herein. In thisparticular example, the therapeutic target is actually a particular typeof cell 4 b (open irregular spheres), for example, a nerve cell, orendocrine secretory cell; and these cells are distributed throughout thetarget area. The post-ablation therapeutic target cells 4 a (darkirregular spheres) are those which happened to be included within theconical regions 3 a that were ablated. The post-ablation cells 4 a maybe rendered dysfunctional to varying degree, they may be completelydysfunctional, they may be, merely by way of illustrative example, onthe average, 50% functional by some measure, and there functionality mayvary over a particular range. It should be particularly appreciatedhowever, per embodiments of the invention, that the cells 4 b, those notincluded in the ablated tissue cones, are fully functional.

Controlling the Ablation in Terms of the Tissue Depth of the AblationEffect

In addition to controlling the surface area distribution of ablation, asmay be accomplished by the use of fractional ablation electrodes asdescribed above, or as controlled by the surface area of electrodedimensions, ablation can be controlled with regard to the depth of theablation below the level of the tissue surface where the ablativestructure makes therapeutic contact with the tissue. The energy deliveryparameters appropriate for delivering ablation that is controlled withregard to depth in tissue may be determined experimentally. By way ofexample, an experimental set of exercises was performed on normalimmature swine in order to understand the relationship between theelectrical parameters of electrode activation and the resultant level ofablation in esophageal tissue. The data are shown in detail in U.S.application Ser. No. 10/370,645 of Ganz et al, filed on Feb. 19, 2003,and in the publication on Aug. 21, 2003, of that application, US2003/0158550 A1, particularly in Tables 1-4 of that application. By anapproach such as this, appropriate parameters for ablation of othertissues in the bypass-reconstructed gastrointestinal tract may bedetermined. Such parameters as applied by ablational electrode patternson an ablational structure with a 360 degree operating surface that isdirected to esophageal tissue, by way of example, include 300W deliveredwithin 300 msec, with a tightly spaced with tightly spaced bi-polarelectrode array (less than 250 microns). Ablation depth related to theenergy density delivered with 8-12 J/cm2 results in complete removal ofthe epithelium. Such parameters as applied by electrode patterns on anablation structure with an operating radial surface of about 90 degreesincludes multiple narrow band electrodes spaced 250 microns wide, wherethe generator delivers very high power energy density at 40 W/cms to thetissue in an energy dosage of 12-15 J/cm2. In general, depth variancescan be achieved via time of ablation, dosage, number of energyapplications, and electrode spacing.

FIG. 25 provides a schematic representation of the histology of thebypass-reconstructed gastrointestinal wall as it is found in variousluminal organs such as the esophagus, stomach, pylorus, duodenum, andjejunum. The relative presence and depth and composition of the layersdepicted in FIG. 25 vary from organ to organ, but the basic organizationis similar. The layers of the bypass-reconstructed gastrointestinal wallwill be described in their order from the innermost to the outermostlayer facing the bypass-reconstructed gastrointestinal lumen; and asseen FIG. 25 and in terms of the direction from which an ablationalstructure would approach the tissue. The innermost layer can be referredto as the surface (epithelium), and succeeding layers can be understoodas being below or beneath the “upper” layers. The innermost layer of abypass-reconstructed gastrointestinal tract organ, which is in directcontact with the nutrients and processed nutrients as they move throughthe gut is a layer of epithelium 12. This layer secretes mucous whichprotects the lumen from abrasion and against the corrosive effect of anacidic environment. Beneath the epithelium is a layer known as thelamina propria 13, and beneath that, a layer known as the muscularismucosae 14. The epithelium 12, the lamina propria 13, and the muscularismucosae 14 collectively constitute the mucosa 15.

Below the mucosal layer 15 is a layer known as the submucosa 16, whichforms a discrete boundary between the muscosal layer 15 above, and themuscularis propria 17 below. The muscularis propria 17 includes variousdistinct layers of smooth muscle that enwrap the organ, in variousorientations, including oblique, circular, and the longitudinal layers.Enwrapping the muscularis propria 17 is the serosa 18, which marks theouter boundary of the organ.

The entirety of the bypass-reconstructed gastrointestinal tract wall ishighly vascular and innervated. The mucosal layer is particular rich inglands and cells that secrete contents into the lumen and secretehormones into the bloodstream. The nerves in this region are sensitiveto the chemical composition of the nutrient flow, as it passes by, andtheir synaptic signals convey information to other organs that areinvolved in nutrient processing, such as the pancreas, and to thecentral nervous system, where information is integrated and regulatesappetite and satiety. Nerve cells, proprioreceptors, in the muscularispropria sense the physical state of the wall, whether it is contractedor extended, and motor neurons in the musculature control the tensionand general motility of the organ. All of these cells, includingvasculature, exocrine cells, endocrine cell, and nerve cells arepotential targets for ablation when ablational energy is directed towardthe region in which they reside. As a result of receiving energy, cellsmay be killed or scarred to an extent that they are no longerfunctional, or they may be partially damaged, leaving some level offunction. Additionally, it should be understood that these cells allexist in populations, and a partial ablation may manifest in astatistical distribution of damage, in which some cells of thepopulation are eliminated or damaged beyond redemption, and some cellsmay remain substantially unaffected, and fully functional. In suchpartial or fractional ablation events, it can be understood that theremnant level of function following therapeutic ablation may include arange of function and dysfunction.

As provided by embodiments of the invention, the ablation applied tobypass-reconstructed gastrointestinal wall tissue may bedepth-controlled, such that only the epithelium 12, or only a portion ofthe mucosal layer is ablated, leaving the deeper layers substantiallyunaffected. In other embodiments, the ablated tissue may commence at theepithelium yet extend deeper into the submucosa and possibly themuscularis propria, as necessary to achieve the desired therapeuticeffect.

Device and Method for Partially-Circumferential Ablation

One embodiment of a method of ablating tissue in thebypass-reconstructed gastrointestinal tract includes the use of anablation device with an ablation structure supported by conventionalendoscopes 111, as illustrated in FIG. 24. As described herein, moreparticularly, the tissue targeted for ablation by embodiments of anablation device and methods therefore is on the wall of thebypass-reconstructed gastrointestinal tract in the lumen of an organsuch as the gastric pouch, stoma, or gastric sleeve. An example of onecommercially available conventional endoscope 111 is the Olympus“gastrovideoscope” model number GIF-Q160. While the specificconstruction of particular commercially available endoscopes may vary,as shown in FIG. 24, most endoscopes include a shaft 164 having asteerable distal end 110 and a hub or handle 162 which includes a visualchannel 161 for connecting to a video screen 160 and a port 166providing access to an inner working channel within the shaft 164.Dials, levers, or other mechanisms (not shown) will usually be providedon the handle 162 to allow an operator to selectively steer the distalend 110 of the endoscope 111 as is well known in the endoscopic arts. Inaccordance with the present invention, an ablation device, including anablation structure is advanced into the bypass-reconstructedgastrointestinal tract while supported at the distal end of anendoscope. The ablation structure is deflectable toward a tissue surfaceand the ablation structure is activated to ablate the tissue surface.Within the bypass-reconstructed gastrointestinal tract, variously sizedtissue surface sites can selectively be ablated using the device. Aswill be further described, the ablational structure of embodimentsdescribed in this section do not circumscribe a full 360 degrees, butrather circumscribe a fraction of 360 degrees, as will be describedfurther below.

In general, in one aspect a method of ablating tissue in thebypass-reconstructed gastrointestinal tract is provided. The methodincludes advancing an ablation structure into the bypass-reconstructedgastrointestinal tract while supporting the ablation structure with anendoscope. In some embodiments, advancing the structure into thebypass-reconstructed gastrointestinal may be sufficient to place theablational structure of the device into close enough proximity in orderto achieve therapeutic contact. In other embodiments, a subsequent stepmay be undertaken in order to achieve an appropriate level oftherapeutic contact. This optional step will be generally be understoodas moving the ablation structure toward the target site. The method thusmay further include moving at least part of the ablation structure withrespect to the endoscope and toward a tissue surface; and activating theablation structure to ablate the tissue surface. Moving at least part ofthe ablation structure with respect to the endoscope can includemovement toward, away from or along the endoscope. Moving the ablationalstructure toward a target tissue surface may be performed by structuresin ways particular to the structure. For example, the structure can bemoved by inflating a balloon member, expanding a deflection member, ormoving a deflection member. The function of such movement is toestablish a therapeutically effective contact between the ablationalstructure and the target site. A therapeutically effective contactincludes the contact being substantial and uniform such that the highlycontrolled electrical parameters of radiant emission from the electroderesult in similarly highly controlled tissue ablation. Some embodimentsof the invention further include structure and method for locking orsecuring such a therapeutically effective contact once established.Thus, some embodiments include a position locking step that, forexample, uses suction to secure the connection between the ablationstructure and the tissue site.

As shown in FIGS. 9, 10, 11, and 26, in one aspect a method of ablatingtissue in the a reconstructed gastrointestinal tract feature includes anablation device 100 for ablating a tissue surface 3, wherein the device100 includes an ablating structure, for example, an ablation structure101 supported by an endoscope 111. The method includes ablating tissuein the wall of a luminal organ of the bypass-reconstructedgastrointestinal tract by the steps of (1) advancing the ablationstructure 101 into the luminal organ; (2) deflecting the ablationstructure 101 toward a tissue surface 3; and (3) activating the ablationstructure to ablate the tissue surface 3. As shown in FIG. 9, the device100 can additionally include a housing 107, electrical connections 109,an inflation line 113 and an inflation member or balloon 105.

The ablation structure 101, in one embodiment is an electrode structureconfigured and arranged to deliver energy comprising radiofrequencyenergy to the mucosal layer of the wall of the organ of thebypass-reconstructed gastrointestinal tract. It is envisioned that suchan ablation structure 101 can include a plurality of electrodes. Forexample, two or more electrodes may be part of an ablation structure.The energy may be delivered at appropriate levels to accomplish ablationof mucosal or submucosal level tissue, or alternatively to causetherapeutic injury to these tissues, while substantially preservingmuscularis tissue. The term “ablation” as used herein generally refersto thermal damage to the tissue causing any of loss of function that ischaracteristic of the tissue, or tissue necrosis. Thermal damage can beachieved through heating tissue or cooling tissue (i.e. freezing). Insome embodiments ablation is designed to be a partial ablation.

Although radiofrequency energy, as provided by embodiments of theinvention, is one particular form of energy for ablation, otherembodiments may utilize other energy forms including, for example,microwave energy, or photonic or radiant sources such as infrared orultraviolet light, the latter possibly in combination with improvedsensitizing agents. Photonic sources can include semiconductor emitters,lasers, and other such sources. Light energy may be either collimated ornon-collimated. Other embodiments of this invention may utilize heatablefluids, or, alternatively, a cooling medium, including such non-limitingexamples as liquid nitrogen, Freon™, non-CFC refrigerants, CO₂ or N₂O asan ablation energy medium. For ablations using hot or cold fluids orgases, the ablation system may include an apparatus to circulate theheating/cool medium from outside the patient to the heating/coolingballoon or other element and then back outside the patient again.Mechanisms for circulating media in cryosurgical probes are well knownin the ablation arts. For example, and incorporated by reference herein,suitable circulating mechanisms are disclosed in U.S. Pat. No. 6,182,666to Dobak; U.S. Pat. No. 6,193,644 to Dobak; U.S. Pat. No. 6,237,355 toLi; and U.S. Pat. No. 6,572,610 to Kovalcheck.

In a particular embodiment, the energy delivered to the wall of aluminal organ of the bypass-reconstructed gastrointestinal tractcomprises radiofrequency energy that can be delivered from the energydelivery device 100. Radiofrequency energy can be delivered in a numberof ways. Typically, the radiofrequency energy will be delivered in abipolar fashion from a bipolar array of electrodes positioned on theablation structure 101, in some cases on an expandable structure, suchas a balloon, frame, cage, or the like, which can expand and deploy theelectrodes directly against or immediately adjacent to the mucosaltissue so as to establish a controlled level of therapeutic contactbetween the electrodes and the target tissue (e.g., through directcontact or through a dielectric membrane or other layer). Alternatively,the electrode structure may include a monopolar electrode structureenergized by a radiofrequency power supply in combination with a returnelectrode typically positioned on the patient's skin, for example, onthe small of the back. In any case, the radiofrequency energy istypically delivered at a high energy flux over a very short period oftime in order to injure or ablate only the mucosal or submucosal levelsof tissue without substantially heating or otherwise damaging themuscularis tissue. In embodiments where the ablation structure includesa plurality of electrodes, one or more of the electrodes can be bipolaror monopolar, and some embodiments include combinations of bipolar andmonopolar electrodes.

The ablation structure 101 can be arranged and configured in any of anumber ways with regard to shape and size. Typically, the array has anarea in the range from about 0.5 cm² to about 9.0 cm². Typical shapeswould include rectangular, circular or oval. In one embodiment, theablation structure 101 has an area of about 2.5 cm². In anotherembodiment, the ablation structure 101 has an area of about 4 cm² anddimensions of about 2 cm. by 2 cm.

The housing 107 of the ablation device 100 is arranged and configured tosupport the ablation structure 101. The housing 107 can be made of anysuitable material for withstanding the high energy flux produced by theablation structure 101. As shown in FIGS. 9-14, 17, 18, 21, and 22, inone embodiment, the housing 107 is sandwiched between the ablationstructure 101 and an endoscope 111 when the ablation device 100 issupported by an endoscope 111. One end of the ablation structure 101 canbe further away from the endoscope than the other end to improve ease ofcontact with the targeted tissue (not shown). For example, to ensure theproximal end of the ablation structure 101 makes contact with thetargeted tissue, the proximal end of the electrode may be supported by atapered housing member 107.

The electrical connections 109 of the ablation device connect theablation structure 101 to a power source. The electrical connections 109can include a single wire or plurality of wires as needed to providecontrolled energy delivery through the ablation structure 101. In oneembodiment, the electrical connections 109 include low electrical losswires such as litz wire.

The inflation line 113 is arranged and configured to transport anexpansion medium, typically a suitable fluid or gas, to and from theinflation member. In one embodiment, the inflation line is a flexibletube. The inflation line 113 can be made of polymer or co-polymers, suchas the non-limiting examples of polyimide, polyurethane, polyethyleneterephthalate (PET), or polyamides (nylon). The inflation member 105 isdesigned to deflect the ablation device 100 in relation to a targettissue surface 3. The inflation member 105 can be reversibly expanded toan increased profile.

In one embodiment, the inflation member 105 additionally serves as anattachment site for support of the ablation device 100 by an endoscope111. As shown in FIGS. 9-14, 17, 18, 21 and 22, the inflation member 105can be deployed from a low profile configuration or arrangement (seeFIGS. 10, and 20) to an increased profile configuration or arrangement(see FIGS. 11-14, 17-19) using the expansion medium. In preparation forablation, when the inflation member 105 is sufficiently inflated,deflection of the ablation device 100 in relation to a tissue surface 3can be achieved. As shown in FIGS. 11, 31, 42, and 44, in oneembodiment, deflection of the ablation device 100 results in atherapeutic level of contact, i.e., a substantially direct, uniform, andsustainable contact between the ablation structure 101 of the device 100and the target tissue surface 3. For example, as shown in FIGS. 31, 42,and 44, when the inflation member 105 is sufficiently inflated, theresulting expanded profile of the inflation member 105, which contactsthe tissue surface 3, results in contact by deflection between thetissue surface 3 of the inner wall of a luminal organbypass-reconstructed gastrointestinal tract 5 and the ablation structure100. In these embodiments, suction can be applied in combination withthe inflation member 105 to achieve contact between the ablationstructure 101 and the tissue surface 3. Suction can be achieved throughthe endoscope 111 or through the ablation device 100 to aid incollapsing the targeted tissue surface 3 around the ablation structure101.

In various embodiments, the inflation member 105 may be compliant,non-compliant or semi-compliant. The inflation member 105 can be made ofa thin, flexible, bladder made of a material such as a polymer, as byway of non-limiting examples, polyimide, polyurethane, or polyethyleneterephthalate (PET). In one embodiment, the inflation member is aballoon. Inflation of the inflation member 105 can be achieved throughthe inflation line 113 using, for example, controlled delivery of fluidor gas expansion medium. The expansion medium can include a compressiblegaseous medium such as air. The expansion medium may alternativelycomprise an incompressible fluid medium, such as water or a salinesolution.

As shown in FIGS. 12, 13, and 14, the inflation member 105 can beconfigured and arranged in a variety of ways to facilitate deflection ofthe ablation device 100 in relation to a tissue surface 3. For example,as shown in FIG. 12, the inflation member 105 can be eccentricallypositioned in relation to the supporting endoscope 111 as well as thehousing 107 and the ablation structure 101. Alternatively, as shown inFIG. 13, the inflation member 105 can be positioned concentrically inrelation to the supporting endoscope 111 and the ablation structure 101can be attached to the inflation member 105 distally from the endoscope111. In another embodiment, as shown in FIG. 12, the inflation member105 can be positioned between the supporting endoscope 111 and theablation structure 101. The ablation structure 101 shown in FIGS. 12-14can cover a range of circumferential span of the endoscope 111 spanning,for example, from about 5 to 360 degrees when inflation member 105 isdeployed.

One method of ablating tissue in a luminal organ of thebypass-reconstructed gastrointestinal tract can include a first step ofadvancing an ablation structure 101, into the bypass-reconstructedgastrointestinal tract. In a second step, the ablation structure 101 issupported with an endoscope 111 within the bypass-reconstructedgastrointestinal tract. In a third step, the ablation structure 101 isdeflected toward a tissue surface 3. In a fourth step, energy can beapplied to the ablation structure 101 to ablate the tissue surface 3.

In another method, the step of advancing an endoscope-supported ablationstructure 101 can include advancing the endoscope 111 into a luminalorgan of the bypass-reconstructed gastrointestinal tract and advancingthe ablation structure 101 over the endoscope 111. For example, theendoscope 111 can be positioned relative to an ablation target tissuesurface 3 after which the ablation structure 101 can be advanced overthe outside of the endoscope 111 for ablating the target tissue surface3.

In a further method, the step of supporting the ablation structure 101with an endoscope 111 includes inserting the endoscope 111 into theablation structure 101 (see for example, FIGS. 1A-2B). In a relatedmethod, the ablation structure 101 is supported by a sheath 103 (seeFIGS. 26-28, 30, 31, 32 and 37) and the step of inserting the endoscope111 into the ablation structure 101 includes inserting the endoscope 111into the sheath 103. In a further related method, the step of insertingthe endoscope 111 into the sheath 103 includes creating an opening inthe sheath 103 (not shown).

In a particular method, a distal portion of a sheath 103 having asmaller outer diameter than a proximal portion of the sheath 103, isadapted to be expanded when an endoscope 111 is inserted into it.

In another method, the step of advancing the ablation structure 101 intothe bypass reconstructed gastrointestinal tract includes advancing theablation structure 101 through a channel of the endoscope 111 fromeither the endoscopes proximal or distal end (as discussed below forFIGS. 34A, 35A and 36A). In yet another method, the step of supportingthe ablation structure 101 comprises supporting the ablation structure101 with a channel of the endoscope (see as discussed below for FIGS.34A, 35A, 36A, 37-39). In a further method, a deflection structure ordeflection member 150 is advanced through a channel of the endoscope 111and the step of deflecting the ablation structure 101 toward a tissuesurface 3 includes deflecting the ablation structure 101 with thedeflection structure or deflection member 150.

As illustrated in FIGS. 34A, 35A, and 36A, variously adapted andconfigured ablation structures 101 can fit within and be conveyedthrough an endoscope internal working channel 211. In each case, theablation structure 101 and an accompanying deflection mechanism can beconveyed through the internal working channel 211 in a dimensionallycompacted first configuration that is capable of expansion to a secondradially expanded configuration upon exiting the distal end 110 of theendoscope 111 (For example, see FIGS. 34A, 34B, 35A, 35B, 36A, and 36B).

As shown in FIG. 34B, in one embodiment, the deflection mechanism is aninflation member 105, to which the ablation structure 101 can beintegrated within or mounted/attached to, for example by etching,mounting or bonding. The inflation member 105 can be, for example, acompliant, non-compliant or semi-compliant balloon.

As shown in FIGS. 35B and 35B, in another embodiment, the deflectionmechanism is an expandable member 209 that can expand to a seconddesired arrangement and configuration. As shown in FIG. 35B, theexpandable member 209, can be an expandable stent, frame or cage device,to which an ablation structure 101 is mounted or integrated. Forexample, where the expandable member 209 is a wire cage, the wires canbe a component of a bipolar circuit to provide the ablation structure101 feature. Alternatively, the cage can have a flexible electrodecircuit bonded or can be attached to an outer or inner surface of thecage to provide an ablation structure 101 that is an electrode. As shownin FIG. 36B, the expandable member 209, can be a folded or rolled seriesof hoops including or having an attached ablation structure 101 thatexpands upon exiting the endoscope distal end 110.

As further illustrated in FIGS. 37-39, the ablation structure 101 can besupported with a channel of the endoscope 111. In one embodiment asshown in FIGS. 37-39, an ablation device 100 includes a deflectionmember 150 that supports an attached housing 107 and ablation structure101. As shown in FIG. 39, the endoscope 111 includes an internal workingchannel 211 suitable for advancing or retreating the deflection member150 which is connected to an internal coupling mechanism 215 of theablation device 100. FIGS. 37 and 39 both show a deflection member 150including a bent region of the deflection member 150 in a deployedposition, wherein the deflection member 150 bent region is positionedexternal to the endoscope distal end 110. FIG. 38 shows the deflectionmember 150 in an undeployed position, wherein the deflection member 150bent region is positioned internal to the endoscope 111. The ablationstructure 101 is thus supported with a channel of the endoscope 111 (theinternal working channel 211 of the endoscope 111) by way of thedeflection member 150 and the connected internal coupling mechanism 215of the ablation device 100.

In addition, when the deflection member 150 is advanced or movedproximally or distally within the endoscope internal working channel211, the deflection member 150 is accordingly advanced through a channelof the endoscope 111. In another implementation, as shown in FIG. 42,wherein the deflection mechanism is an inflatable member 105 (shown in adeployed configuration) coupled to an inflation line 113, the inflationline 113 can be disposed within the endoscope internal working channel211. In yet another implementation, both the inflatable member 105 (inan undeployed configuration) and inflation line 113 can be advancedwithin the internal working channel 211 either proximally or distally inrelation to the endoscope 111. Conductive wires 109 can pass through theworking channel (not shown) or outside as shown in FIG. 37.

As shown in FIG. 41, in another implementation the endoscope 111includes an internal working channel 211 suitable for supporting theablation housing 107 and ablation structure 101 which are connected toan internal coupling mechanism 215 of the ablation device 100. As such,the connected ablation structure 101 is supported within a channel ofthe endoscope 111. Additionally as shown in FIG. 41, the housing 107 andablation structure 101 can further be supported by an external region ofthe endoscope 111, wherein the internal coupling mechanism 215 isadapted and configured to position the housing 107 in contact with theexternal region of the endoscope 111. The internal coupling mechanism215 can be cannulated (not shown) to facilitate use of the workingchannel to aspirate and flow in fluids or air.

In another ablation method, an additional step includes moving theablation structure 101 with respect to the endoscope 111 within aluminal organ of the bypass-reconstructed gastrointestinal tract. Asillustrated in FIGS. 27, 28, 30, 32, and 47, and as discussed below, asheath 103 of the ablation device 100 to which the ablation structure101 is attached can enable moving the ablation structure 101 withrespect to the endoscope 111. Further, as illustrated in FIGS. 34A, 35A,36A, 37, 38, 39, and 41, and discussed above, an internal workingchannel 211 of the endoscope 111 through which at least a part of theablation device 100 is disposed can enable moving the ablationsstructure 101 with respect to the endoscope 111.

Referring to FIGS. 11, 31, 42, and 44, in yet another method, the stepof deflecting the ablation structure 101 toward a tissue surface 3includes inflating an inflation member 105 of the ablation device 100within a luminal organ of the bypass-reconstructed gastrointestinaltract. The inflation member 105 can be arranged and configured to bereversibly inflatable. The inflation member 105 can be inserted alongwith the ablation structure 101 into an alimentary tract in a collapsedconfiguration and expanded upon localization at a pre-selected treatmentarea. In one implementation, the inflation member 105 is a balloon. Forexample, in FIGS. 11, 31, 42, and 44 it is shown how deflecting theablation structure 101 toward a tissue surface 3 is achieved when theinflation member 105 is inflated or deployed. As illustrated in FIGS.11, 31, 42, and 44, upon sufficient inflation, the inflation member 105contacts a tissue surface 3 consequently deflecting the ablationstructure 101 which contacts an opposing tissue surface 3.

As shown in FIGS. 19B, 20, 35, 36 and discussed above, in a furthermethod, the step of deflecting the ablation structure 101 includesexpanding a deflection structure or deflection member 150. In oneimplementation, as shown in FIG. 19A the ablation device 100 includes asheath 103, wherein the sheath 103 is arranged and configured to receivethe deflection member 150, the endoscope 111 and ablation structure 101internally to the sheath 103. In one implementation, the deflectionmember 150 is a shape memory alloy, for example, Nitinol. The flexibleextensions of the deflection member 150 in this embodiment can becoupled to the endoscope, an elastomeric sheath 115 of the ablationdevice 100 (shown in FIG. 19A) or any part of the device 100, includingthe ablation housing 107.

As shown in FIGS. 34, 35, 36, 37, 38, and 39, and discussed above, in afurther method, the step of deflecting the ablation structure 101includes moving a deflection structure or deflection member 150.

Briefly, in each case moving the deflection 150 is used to change thedeflection member 150 from a non-deployed to a deployed configuration.As shown in FIG. 23, in one embodiment, deflecting the ablationstructure 101 includes a flexing point in the ablation structure 101,wherein the ablation structure 101 can deflect in response to, forexample, resistance met in contacting a tissue surface 3.

As shown in FIGS. 43, 44, and 45A-45C and as discussed in further detailbelow, in another method, the step of deflecting the ablation structure101 includes rotating, pivoting, turning or spinning the ablationstructure 101 with respect to the endoscope 111 along their respectiveand parallel longitudinal axes. Deflection of the ablation structure 101with respect to the endoscope 111 can occur in combination with theendoscope 111 distal end 110 deflecting with respect to a target site onthe wall of an luminal organ of the bypass-reconstructedgastrointestinal tract or without. Also, the ablation structure 101 candeflect in combination with an inflation member 105 used to achieveapposition of the ablation device 100 to the tissue. In someembodiments, the step of deflecting the ablation structure 101 mayadditionally include any combination of the above disclosed deflectingsteps.

As shown in FIGS. 19, 20, 21, 22, 34A, 34B, 35A, 35B, 36A, 36B, 46B, and47, in another ablation method, an additional step includes moving theablation structure 101 from a first configuration to a second radiallyexpanded configuration. The details regarding radial expansion of theablation structure 101 shown in FIGS. 19, 20, 21, and 22 are describedbelow, while the details for FIGS. 34A, 34B, 35A, 35B, 36A, and 36B aredescribed above. Additionally, as shown in FIGS. 46B and 47 the ablationstructure 101 can be arranged in a first configuration wherein theablation structure 101 is coupled directly or alternatively through anhousing 107 (not shown) to an inflation member 105 attached to acatheter 254. In an undeployed configuration as shown in FIGS. 46B and47, the non-inflated inflation member 105 and ablation structure 101have a relatively low profile in relation to the endoscope 111. Whendeployed, the inflation member 105 moves the ablation structure 101 to asecond radially expanded configuration (not shown).

As shown in FIGS. 15, 16, 40, 43, 44, 45A-45C, 46B, and 47, in a furthermethod, an additional step includes attaching the ablation structure 101to the endoscope 111. As shown in FIGS. 15 and 16, attachment of theablation structure 101 to the endoscope 111 can also be by way of anelastomeric sheath 115 The elastomeric sheath 115 can removably hold theablation structure 101 in a desired position on the endoscope 111. Theelastomeric sheath 115 can be arranged and configured to fit over theendoscope distal end 110. As shown in FIGS. 15 and 16, the inflationmember 105 can be attached to the elastomeric sheath 115 oralternatively the inflation member 105 can also act as the “elastomericsheath” (not shown).

In another method, the step of attaching the ablation structure 101 tothe endoscope 111 includes attaching the ablation structure 101 to anoutside surface of the endoscope. Alternatively, the attaching step caninclude, for example, attaching to an inside surface, an outside orinside feature of the endoscope, or any combinations of the above.Lubricants such as water, IPA, jelly, or oil may be use to aidattachment and removal of the ablation device from the endoscope.

As shown in FIG. 41, in a further method, the step of attaching theablation structure 101 to the endoscope 111, includes an ablationstructure 101 having an attached rolled sheath 116, wherein attachingthe ablation structure 101 to the endoscope 111 includes unrolling thesheath 116 over an outside surface of the endoscope 111. The rolledsheath 116 can additionally cover the electrical connections 109 of theablation device 100 along a length of the endoscope 111 (see FIG. 41).In a related method, the ablation structure 101 is attached to theendoscope 111 by an attaching step including unrolling the rolled sheath116 over an outside surface of the endoscope 111 and part of theablation structure 101.

In another method, as shown in FIG. 40, the step of attaching theablation structure 101 to the endoscope 111 includes attaching theablation structure 101 to a channel of the endoscope. As shown in FIG.40, in one implementation, the housing 107 and ablation structure 101are coupled to an internal coupling mechanism 215 that can be positionedwithin an internal working channel 211 of the endoscope 111. Theinternal coupling mechanism 215 in FIG. 40 is shown as attached to theinternal working channel 211 at the endoscope distal end 110. In thisembodiment, the housing 107 and ablation structure 101 are shown inalignment with and coupled to an outside surface of the endoscope 111near the distal end 110.

In one method of ablating tissue in the alimentary tract, the tissuesurface 3 can include a first treatment area and activation of theablation structure 101 step can include activation of the ablationstructure 101 to ablate the first treatment area, and further includemoving the ablation structure 101 to a second area without removing theablation structure 101 from the patient and activating the ablationstructure 101 to ablate the second tissue area 3. Moving, in this sense,refers to moving the ablational structure to the locale of a targetsite, and thereafter, further moving of the structure into atherapeutically effected position can be performed variously byinflating a balloon member, or deflection or inflating a deflectionmember, as described in detail elsewhere. For example, where two or moreareas of the tissue surface 3 of a target area in the wall of an organin the bypass-reconstructed gastrointestinal tract can be ablated bydirecting the ablation structure 101 to the first target region and thenactivating the ablation structure 101 to ablate the tissue surface 3.Then, without removing the ablation structure 101 from the patient, theablation structure 101 can be directed to the second target area in thewall of an organ for ablation of the appropriate region of the tissuesurface 3.

In general, in another aspect, an ablation device 100 is provided thatincludes an ablation structure 101 removably coupled to an endoscopedistal end 110, and a deflection mechanism adapted and configured tomove the ablation structure 101 toward a tissue surface 3 (see forexample, FIGS. 5-19, 22, 22, 27-29, 30-32, 34A, 35A, 36A, 37, 38, 39,42, 44, and 47).

In a related embodiment, the ablation device 100 additionally includesan ablation structure movement mechanism adapted to move the ablationstructure 101 with respect to the endoscope 111. As discussed below andshown in FIGS. 26-28, and 30-32, the ablation structure movementmechanism can be a sheath 103 to which the ablation structure 101 isattached, wherein the sheath 103 is arranged and configured to move theablation structure 101 with respect to an endoscope 111 received withinthe sheath 103. Alternatively, as discussed above and shown in FIGS.34A, 35A, 36A, and 37-39, the ablation structure movement mechanism canbe in the form of an internal coupling mechanism 215 of the ablationstructure 100, wherein the ablation structure is connected to theinternal coupling mechanism 215 and at least a portion of the internalcoupling mechanism 215 is disposed internally to the endoscope.

In another embodiment, the ablation device 100 additionally includes acoupling mechanism designed to fit over an outside surface of anendoscope 111, to couple the ablation structure 101 with the endoscope111. As discussed above, a spiral sheath 104, an elastomeric sheath 115,a rolled sheath 116 and an internal coupling mechanism as shown in FIGS.15, 16, 40, and 41 respectively, are examples of such couplingmechanisms. In a particular embodiment, the coupling mechanism includesa sheath 103 capable of supporting the ablation structure 101. Thesheath 103 can be tubing, a catheter or other suitable elongate members.The sheath 103 can be arranged and configured so that it can be movedindependently of an associated endoscope.

As shown in FIG. 41, in another embodiment, the sheath 103 can bearranged and configured as a rolled sheath 116 that can be unrolled overthe outside surface of the endoscope. In use, a rolled sheath 116connected to the ablation device 100, for example at substantially nearthe proximal end of the housing 107 (from the perspective of an operatorof the device), can be unrolled from such a position and continue to beunrolled toward the proximal end 112 of the endoscope 111 (see FIG. 47).In this way, the rolled sheath 116 can be caused to contact and coverall or a portion of the length of the endoscope 111 (not shown).Additionally, as the rolled sheath 116 is unrolled along the endoscope111, it can sandwich the electrical connections 109 between the rolledsheath 116 and the endoscope 111 (see generally FIG. 41).

In another embodiment, as shown in FIGS. 30 and 31, the sheath 103 canbe arranged and configured to support a deflection mechanism wherein thedeflection mechanism includes a deflection structure or deflectionmember 150. As illustrated in FIGS. 30 and 31, where the deflectionmember 150 is an inflation member 105, the inflation member 105 can bedirectly attached to the sheath 103. As shown in each case, theinflation member 105 is positioned opposite the placement of theablation structure 101, which is also attached to the sheath 103. Thisconfiguration of the sheath 103 provides support for the inflationmember 105 and the ablation structure 101 irrespective of thepositioning of the endoscope distal end 110. For example, as shown inFIG. 30, the endoscope distal end 110 can be positioned to provide a gapbetween the distal end 110 and a distal end of the sheath 103 where theablation structure 101 and inflation member 105 are positioned. Incontrast, as shown in FIG. 31 the endoscope distal end 110 can extendthrough and beyond the distal end of the sheath 103.

In another embodiment, as shown in FIG. 26, the sheath 103 can beelongated. FIG. 26 illustrates a sheath including electrical connections109 and an inflation line 113. The sheath 103 may include pneumaticand/or over extruded wires impregnated within the sheath 103. In use,the sheath 103 can be introduced first into an alimentary tract, whereinthe sheath 103 serves as a catheter like guide for introduction of theendoscope 111 within the sheath 103. Alternatively, the endoscope 111may be introduced first and thereby serve as a guidewire for the sheath103 to be introduced over. FIG. 26 also shows attachment of an inflationmember 105 to the sheath 103, in an arrangement wherein the ablationstructure 101 is attached to the inflation member 105 opposite thesheath 103 attachment point.

In embodiments shown in FIGS. 27 and 28, the sheath 103 includes anoptically transmissive portion 158 adapted and configured to cooperatewith a visual channel of an endoscope 111. For example, the sheath 103may be made of clear, translucent or transparent polymeric tubingincluding PVC, acrylic, and Pebax® (a polyether block amide). As shownin FIG. 24, one component of an endoscope 111 can be a visual channel161 that provides visual imaging of a tissue surface 3 as imaged fromthe endoscope distal end 110. For example, the transmissive portion 158can allow visualization of the wall of an esophagus 3 through thetransmissive portion 158 of the sheath 103. As shown in FIG. 28 and inthe cross-section view provided in FIG. 29, the sheaths 103 shown inFIGS. 27 and 28, include an optically transmissive portion 158 arrangedand configured to provide viewing of tissue surfaces 3 through the wallof the sheath 103, with the aid of an internally disposed endoscope 111having a visual channel 161. Also shown in cross-section in FIG. 29 areportions of the sheath 103 through which electrical connections 109 andan inflation line 113 can pass. These features may be imbedded into thesheath 103 inner-wall or attached to the sheath 103 inner wall. As shownin FIG. 27, the sheath 103 including a transmissive portion 158 canextend past the endoscope distal tip 110. Alternatively, as shown inFIGS. 27, 28, and 31, the endoscope distal end 110 can extend distallypast the transmissive portion 158 of the sheath 103.

In another implementation, the transmissive portion 158 of the sheath103 can be reinforced structurally with coil or braid elementsincorporated therein to prevent ovalization and/or collapsing of thesheath 103, particularly while deflecting the ablation device 100

In a further embodiment, the sheath 103 includes a slit 203 formed in aproximal portion of the sheath 103, the slit 203 being designed to opento admit an endoscope distal end 110 into the sheath 103. As shown inFIG. 32 the proximal portion of the sheath 103 can include a perforationregion or slit 203. The slit 203 can extend partially of fully along thelength of the sheath 103. The slit 203 enables the sheath 103 to bepulled back, or opened when, for example introducing an endoscope 111into the sheath 103. In one implementation, as shown in FIG. 32, thesheath 103 additionally includes a locking collar 205 for locking thesheath 103 in a desired position in respect to the endoscope 111.

As shown in FIGS. 33A and 33B, the distal portion of the sheath 103 canhave a smaller outer diameter than a, proximal portion of the sheath103, the distal portion of the sheath 103 being adapted and configuredto be expanded when an endoscope 111 is inserted into it (not shown).This embodiment can aid in accessing an endoscope 111 in a case wherethe sheath 103 is advanced first into a target site within thealimentary tract. Since the distal end of the sheath 103 is smaller indiameter, but includes a slit 203, the sheath 103 can accept a largeroutside diameter endoscope 111 because when the endoscope 111 isadvanced, the slit 203 of the sheath 103 allows for widening of thesheath 103.

In general, in another aspect, a method of ablating tissue in within thealimentary tract includes advancing an ablation structure 101 into thealimentary tract while supporting the ablation structure 101 with anendoscope 111. The endoscope distal end 110 can be bent to move theablation structure 101 into contact with a tissue surface followed byactivation of the ablation structure 101 to ablate the tissue surface 3(see e.g., FIG. 43). In a particular embodiment, the ablation structure101 includes a plurality of electrodes and the activating step includesapplying energy to the electrodes.

In general, in another aspect the coupling mechanism is designed to fitover an outside surface of an endoscope 111, to couple the ablationstructure 101 with the endoscope 111, rather than being for example, asheath (as discussed above), and is adapted and configured to provide acertain freedom of movement to the ablation structure 101, including butnot limited to flexing and/or rotating and/or pivoting with respect tothe endoscope 111 when coupled to the endoscope 111. The freedom ofmovement is with respect to one, two, or three axes, thereby providingone, two, or three degrees of freedom. Non-limiting examples of suitablecoupling mechanisms include a flex joint, pin joint, U-joint, balljoint, or any combination thereof. The following described couplingmechanism embodiments advantageously provide for a substantially uniformapposition force between a supporting endoscope 111 and an ablationstructure 101 when localized at a target tissue surface 3.

As shown in FIGS. 43, 44, 45A, and 45B, the coupling mechanism can be aring 250 attached to the housing 107 and the endoscope 111, wherein thehousing 107 is adapted and configured to flex, rotate or pivot about thering 250. For example, as illustrated in FIG. 43, where the ablationdevice 100 is coupled to a deflectable distal end 110 of an endoscope111 by a ring 250, when the device 100 is deflected toward the tissuesurface 3 of the wall of the lumen of a bypass-reconstructedgastrointestinal organ, the housing 107 upon contact aligns the ablationstructure 101 with the tissue surface 3 by flexing, rotating or pivotingabout the ring 250 coupling. In these embodiments, the endoscope and thehousing that supports the ablation structure both have their ownlongitudinal axis, and these axes are situated parallel to each other.The coupling mechanism that attaches the housing to the endoscope allowsa pivoting movement between the longitudinal axis of the housing and thelongitudinal axis of the endoscope. Advantageously, sufficient contactpressure provided by deflection of the distal end 110 of the endoscope101 can produce a desired degree of contact between the ablationstructure 101 and the tissue surface 3, irrespective of the precisealignment of the distal end 112 in respect to a plane of the tissuesurface 3 to be treated.

For the purposes of this disclosure, a “desired degree of contact”,“desired contact”, “therapeutic contact”, or “therapeutically effectivecontact” between the ablation structure 101 and the tissue surface 3,includes complete or substantially-complete contact between all or aportion of a predetermined target on the tissue surface 3 (e.g. a siteon the wall of a luminal organ of the bypass-reconstructedgastrointestinal tract) by all or a portion of the ablation structure101. It should also be understood that therapeutic contact, as describedin this disclosure typically occurs as a consequence of an ablationalsurface on an apparatus having been moved into such contact by theexpansion of an expandable member such as a balloon, or by expanding,moving, or deflecting a deflection structure. By all such approaches,such movement or bringing into therapeutic contact includes the exertionor application of pressure. Such pressuring is a factor in effectingcoaptive ablation, wherein pressure exerted through tissue on bloodvessels causes them to be partially or substantially emptied of blood,and coincidentally serves as a counter-pressure that prevents entry ofblood normally brought about by blood pressure. Thus, any occurrence ofmoving or expanding a member so as to bring an ablation surface againsttarget tissue can also be understood as pressuring the tissue.

As shown in FIG. 44, in a different yet related embodiment, where thedeflection mechanism of the ablation device 100 is an inflatable member105, a ring 250 coupling allows for flexing, rotating or pivoting of thehousing 107 and ablation structure 101. As in the previous case,sufficient contact pressure provided through deflection, here by theinflatable member 105, can produce a desired degree of contact betweenthe ablation structure 101 and the tissue surface 3. Again,advantageously, the desired contact can be achieved irrespective of theprecise alignment of the deflected endoscope 111 distal end 110 inrespect to a plane of the tissue surface 3 to be treated, because of theflexing, rotating or pivoting provided by the ring 250 coupling.

As shown in FIG. 45A, in a related embodiment, the coupling mechanismbetween the ablation device 100 and an endoscope 111 can be an elasticband 252, wherein the housing 107 of the device 100 is flexibly coupledto the elastic band 252. For example, as illustrated in FIG. 45C, wherethe ablation device 100 is coupled to a distal end 110 of an endoscope111 by an elastic band 252, when the device 100 is deflected toward atissue surface 3 of the wall of a luminal organ of thebypass-reconstructed gastrointestinal tract, alignment between thehousing 107 and accordingly the ablation structure 101 and the tissuesurface 3, can be achieved by flexing about the elastic band 252coupling. Once more, advantageously, the desired contact can be achievedirrespective of the precise alignment of the deflected endoscope's 111distal end 110 in respect to a plane of the tissue surface 3 to betreated, because of the flexing capability provided by the elastic band252 coupling.

As shown in FIG. 45A, in another related embodiment, the couplingmechanism between the ablation device 100 and an endoscope 111 can be acombination of a ring 250 and an elastic band 252, wherein the housing107 of the device 100 is coupled to the elastic band 252. For example,as illustrated in FIG. 45A, where the ablation device 100 is coupled toa distal end 110 of an endoscope 111 by an elastic band 252, when thedevice 100 is deflected toward a tissue surface 3 of, for example, thewall of a luminal organ of the bypass-reconstructed gastrointestinaltract (not shown), alignment between the housing 107 and accordingly theablation structure 101, and the tissue surface 3 by flexing, rotating orpivoting about the ring 250 and the elastic band 252 coupling can beachieved. Again, advantageously, the desired contact can be achievedirrespective of the precise alignment of the deflected endoscope 111distal end 110 in respect to a plane of the tissue surface 3 to betreated, because of the flexing rotating or pivoting provided by theelastic band 252 coupling.

In another embodiment, the ablation device 100 additionally includes analternative coupling mechanism between the ablation device 100 and anendoscope 111 that is arranged and configured to fit within a channel ofan endoscope 111. The coupling mechanism can be an internal couplingmechanism 215 and can be configured and arranged to couple the ablationstructure 101 within an internal working channel 211 of an endoscope 111(see FIG. 37 and as discussed above).

As shown in FIGS. 34A, 34B, 35A, 35B, 36A, and 36B, in one embodiment ofsuch a coupling mechanism, the ablation structure 101 is adapted andconfigured to fit within the endoscope internal working channel 211.Additionally, as shown in FIGS. 34A, 34B, 35A, 35B, 36A, and 36B, in arelated embodiment, the deflection mechanism is also adapted andconfigured to fit within the endoscope internal working channel 211.

In each of the embodiments described above and shown in FIGS. 34A, 34B,35A, 35B, 36A, and 36B, after expansion of the inflatable member 105 orexpandable member 209 and subsequent treatment of a target tissue 3, thecoupling means can further serve as a means to draw, pull or retrievethe ablation structure 101 and deflection mechanism back into theendoscope internal working channel 211. Furthermore, in addition toproviding coupling of the ablation structure 101 with the endoscopeinternal working channel 112, the coupling mechanism can includeelectrical connections 109 to provide energy to the ablation structure101.

In a related embodiment, again wherein the ablation device 100additionally includes a coupling mechanism adapted and configured to fitwithin a channel of an endoscope 111, the coupling mechanism can includea shape memory member and the deflection mechanism can include a bentportion of the shape memory member. As shown in FIGS. 37-39, thecoupling mechanism can be an internal coupling mechanism 215. As shown,the internal coupling mechanism 215 can be disposed within an endoscopeinternal working channel 211 and extend beyond the endoscope distal end100. Additionally, the internal coupling mechanism 215 can be connectedto a deflection mechanism that is a deflection member 150. Thedeflection member 150 can include a bent portion and can be connected tothe housing 107. As shown in FIG. 38 and discussed above, the bentportion of the deflection member 150 can be disposed within theendoscope internal working channel 211, causing the ablation structure101 to move into a non-deployed position. Upon advancing the internalcoupling mechanism 215 toward the endoscope distal end 110, the shapememory nature of the deflection member 150 facilitates deployment of theablation structure 101 to a position suitable for ablation.

In general, in one aspect, the ablation structure 101 of the ablationdevice 100 includes an optically transmissive portion 158 adapted andconfigured to cooperate with a visual channel of an endoscope 111. Asshown in FIGS. 27-31 and discussed above, the optically transmissiveportion 158 can be a sheath 103 of the ablation device 100.

In one embodiment, the ablation structure 101 of the ablation device 100is further adapted and configured to move from a first configuration toa second radially expanded configuration. As shown in FIGS. 19-22, theablation structure 101 and housing 107 can be designed to reversiblymove from a first less radially expanded configuration (see FIGS. 20 and21) to a second radially expanded configuration useful for ablation.Foldable or deflectable configurations that provide for reversibleradial expansion of the housing 107 and the ablation structure 101 canfacilitate access to tissue surfaces because of reduced size.Additionally, foldable or deflectable configurations are helpful inregard to cleaning, introduction, retrieval, and repositioning of thedevice in the luminal organs of the bypass-reconstructedgastrointestinal tract.

The ablation device 100 shown in FIGS. 19B and 20 includes an ablationstructure actuator 152 arranged and configured to move the ablationstructure 101 from the first configuration (see FIG. 20) to a secondradially-expanded configuration (see FIG. 21). As shown (FIGS. 19B and20), the actuator 152 can be elongate and designed to work with areceiver 154 arranged and configured to receive the actuator 152. Theactuator 152 can be a wire, rod or other suitable elongate structure.Alternatively, the actuator 152 can be a hydraulic actuation means withor without a balloon component. In a particular embodiment, the actuator152 is a stiffening wire.

As illustrated in FIG. 20, before the actuator 152 is disposed withinthe portion of receiver 154 attached to the housing 107, both thehousing 107 and the ablation structure 101 are in a first positionhaving a first configuration. As illustrated in FIG. 21, after theactuator 152 is partially or fully introduced into the receiver 154, thehousing 107 and the ablation structure 101 are consequently changed to asecond radially expanded configuration relative to the firstconfiguration. Introduction of the actuator 152 into the receiver 154can force the portions of the housing 107 and ablation structure 101flanking the receiver 154 to expand radially (see FIG. 19). In oneembodiment, the housing 107 is heat set in a flexed first configurationsuitable for positioning the ablation device 100 near a target tissuesurface 3. After a target tissue surface 3 has been reached, theactuator 152 can be introduced into the receiver 154 to achieve thesecond radially expanded configuration which is useful for ablation ofthe tissue surface 3.

In a related alternative embodiment, the housing 107 and ablationstructure 101 include an unconstrained shape that is radially expandedand includes one or more flex points to allow for collapsed or reducedradial expansion when positioned distally to the distal end 110 of anendoscope 111 and compressed by an elastomeric sheath 115 (not shown).

As shown in FIGS. 21 and 22, in another embodiment, the ablationstructure 101 of the ablation device 100 is adapted and configured tomove from a first configuration to a second radially expandedconfiguration wherein the ablation device 100 further includes anexpandable member 156. The expandable member 156 can be positionedbetween the housing 107 and the endoscope 111, where in unexpanded form,the ablation structure 101 is accordingly configured in a firstconfiguration. Upon expansion of the expandable member 156, the ablationstructure 101 configuration is changed to a second radially expandedconfiguration (see FIG. 21).

In one embodiment, the deflection mechanism of the ablation device 100includes an inflatable inflation member 105. As shown in FIGS. 11, 21,22, 25B, 27, 28, 30, 31, 34A, 34B, 42, 44, 46, and 47 and discussedabove, the inflation member 105 can facilitate deflection of the device100 in relation to a tissue surface 3.

In another embodiment, the deflection mechanism includes an expandablemember 156 (see FIGS. 35B and 36B, discussed in detail above). As shownin FIG. 35B, the expandable member 209, can be an expandable stent,frame or cage device. As shown in FIG. 36B, the expandable member 209,can be an expanded series of connected hoops that can be folded orrolled prior to expansion.

In another advantageous embodiment, the ablation device 100 furthercomprises a torque transmission member adapted and configured totransmit torque from a proximal end of the endoscope 111 to the ablationstructure 101 to rotate the ablation structure 101 about a central axisof the endoscope 111. In a particular embodiment, the torquetransmission member includes first and second interlocking membersadapted to resist relative movement between the endoscope 111 and theablation structure 101 about the central axis. As shown in FIGS. 46B,46C, and 47, in one embodiment the first interlocking member is a key258 and the second interlocking member is a keyway 256. In oneembodiment, the first interlocking member is attached to a sheath 103surrounding the endoscope 111 and the second interlocking member isattached to a catheter 254 supporting the ablation structure 101. Forexample, as shown in FIGS. 46B, 46C, and 47, the key 258 can be attachedto a sheath 103 surrounding the endoscope 111 and the keyway 256 can beattached to a catheter 254 supporting the ablation structure 101. In afurther related embodiment, the catheter 254 and sheath 103 are arrangedand configured for relative movement along the central axis of theendoscope 111. The sheath 103 can be, for example, an elastomeric sheathwherein the key 258 is attached to the outside of the sheath 103substantially along a longitudinal axis of the sheath 103 (see FIG.46C). In use, this embodiment provides for a 1-to-1 torque transmissionof the ablation device 100 endoscope assembly 111 when the endoscopeproximal end 112 is manipulated, while also providing for positioning ofthe ablation structure 101 either proximal or distal to the endoscopedistal end 110 in situ. Additionally, the sheath 103 can be pre-loadedinto the catheter 254 or loaded separately.

In general, in one aspect, an ablation device 100 is provided includingan ablation structure 101, and a coupling mechanism adapted to removablycouple the ablation structure 101 to a distal end 110 of an endoscope111 and to permit the ablation structure 101 to rotate and/or pivot withrespect to the endoscope when coupled to the endoscope. Various relatedembodiments wherein, for example, the coupling mechanism comprises aring 250 and the ablation structure 101 is adapted to rotate and/orpivot about the ring 250; wherein the coupling mechanism comprises anelastic band 252 adapted to flex to permit the ablation structure 101 torotate and/or pivot; wherein the ablation device 100 further includes adeflection mechanism adapted and configured to move the ablationstructure 101 toward a tissue surface 3; and, wherein such a deflectionmechanism includes an inflatable member, have been set out in detailabove.

FIG. 56A and 56B provide views of an ablational device with anablational surface on a hinge 159 which acts in a manner similar tomechanism depicted in FIG. 43, and which allows a free pivoting movementof the ablational surface between its longitudinal axis and thelongitudinal axis of an endoscope. FIG. 56A shows the device with theablational surface 101 oriented in parallel with the endoscope, thesurface having made contact with the inner surface of a gastrointestinalluminal wall 5 at a desired target area. The ablation surface 101 issupported by a deflection member 150 that can be expressed from aworking channel, and withdrawn back into a working channel within theendoscope. FIG. 56B shows the device with the longitudinal axis of theablational surface 101 oriented at about a right angle with respect tothe longitudinal axis of the endoscope. This pivoting as a passiveresponse of the ablational surface 101, as it easily rotates on hinge159 through a flexion range of 0 degrees (parallel to the endoscope 111)to about 170 degrees. As shown, the angle of the surface is about 90degrees with respect to the endoscope.

While most embodiments described herein have made use of radiofrequencyenergy as an exemplary ablational energy, and consequently have made useof electrodes as an energy transmitting element, it should be understoodthat these examples are not limiting with regard to energy source andenergy delivery or transmitting elements. As also described herein,other forms of energy, as well as cryoablating approaches, may providefor ablation of target areas in such a manner that ablation isfractional or partial, as described herein, where some portions oftarget area tissue are ablated, and some portions of target area tissueare not substantially ablated.

Terms and Conventions

Unless defined otherwise, all technical terms used herein have the samemeanings as commonly understood by one of ordinary skill in the art ofablational technologies and treatment for metabolic conditions anddiseases, as well as those understood by one of ordinary skill in theart of bariatric surgeries. Specific methods, devices, and materials aredescribed in this application, but any methods and materials similar orequivalent to those described herein can be used in the practice of thepresent invention. While embodiments of the invention have beendescribed in some detail and by way of exemplary illustrations, suchillustration is for purposes of clarity of understanding only, and isnot intended to be limiting. Various terms have been used in thedescription to convey an understanding of the invention; it will beunderstood that the meaning of these various terms extends to commonlinguistic or grammatical variations or forms thereof. It will also beunderstood that when terminology referring to devices, equipment, ordrugs that have been referred to by trade names, brand names, or commonnames, that these terms or names are provided as contemporary examples,and the invention is not limited by such literal scope. Terminology thatis introduced at a later date that may be reasonably understood as aderivative of a contemporary term or designating of a hierarchal subsetembraced by a contemporary term will be understood as having beendescribed by the now contemporary terminology. Further, while sometheoretical considerations have been advanced in furtherance ofproviding an understanding of, for example, the biology of metabolicdisease, or the mechanisms of action of therapeutic ablation, the claimsto the invention are not bound by such theory. Moreover, any one or morefeatures of any embodiment of the invention can be combined with any oneor more other features of any other embodiment of the invention, withoutdeparting from the scope of the invention. Still further, it should beunderstood that the invention is not limited to the embodiments thathave been set forth for purposes of exemplification, but is to bedefined only by a fair reading of claims that are appended to the patentapplication, including the fall range of equivalency to which eachelement thereof is entitled.

1. A method of ablationally-treating tissue in a target area of agastrointestinal tract feature formed by a bariatric procedure that hasfailed comprising: delivering radiofrequency energy to a tissue surfacein the target area, the target area being a contiguous radial portion ofan anatomical structure formed or altered by the bariatric procedure;and controlling the delivery of radiofrequency energy across the tissuesurface in the target area and into tissue layers in the target area. 2.The method of claim 1 wherein bariatric procedure is any of a Roux-en-Yprocedure, a biliopancreatic diversion, or a sleeve gastrectomy.
 3. Themethod of claim 1 wherein the feature of a gastrointestinal tract formedby bariatric procedure is any of a gastric pouch, a stoma, or a gastricsleeve.
 4. The method of claim 3 wherein the feature of agastrointestinal tract formed by bariatric procedure is a suture line ofthe gastric sleeve.
 5. The method of claim 1 wherein deliveringradiofrequency energy includes delivering radiofrequency energy fromnon-penetrating electrodes.
 6. The method of claim 1 wherein controllingthe delivery of radiofrequency energy across the tissue surface in thetarget area includes delivering sufficient radiofrequency energy toachieve ablation in one fraction of the tissue target surface anddelivering insufficient radiofrequency energy to another fraction of thesurface to achieve ablation.
 7. The method of claim 6 whereincontrolling the fraction of the target area surface that receivessufficient radiofrequency energy to achieve ablation includesconfiguring the electrode pattern such that some spacing betweenelectrodes is sufficiently close to allow conveyance of a level ofenergy sufficient to ablate and other spacing between electrodes isinsufficiently close to allow conveyance of the level of energysufficient to ablate.
 8. The method of claim 6 wherein controlling thefraction of the target area surface that receives sufficientradiofrequency energy to achieve ablation includes operating theelectrode pattern such that the energy delivered between some electrodesis sufficient to ablate and energy sufficient to ablate is not deliveredbetween some electrodes.
 9. The method of claim 1 wherein controllingthe delivery of radiofrequency energy into tissue layers includescontrolling the delivery of radiofrequency energy from the tissuesurface such that sufficient energy to achieve ablation is delivered tosome layers and insufficient energy is delivered to other layers toachieve ablation.
 10. The method of claim 1 wherein controlling thedelivery of radiofrequency energy across the surface and into tissuelayers in the target area is such that some fraction of the tissuevolume is ablated and another fraction of the tissue volume is notablated.
 11. The method of claim 1 wherein controlling the delivery ofenergy into tissue layers consists of ablating a fraction of tissue inthe epithelial layer.
 12. The method of claim 1 wherein controlling thedelivery of energy into tissue layers consists of ablating a fraction oftissue in the epithelial layer and the lamina propria.
 13. The method ofclaim 1 wherein controlling the delivery of energy into the tissuelayers consists of ablating a fraction of tissue in the epitheliallayer, the lamina propria, and the muscularis mucosae.
 14. The method ofclaim 1 wherein controlling the delivery of energy into tissue layersconsists of ablating a fraction of tissue in the epithelial layer, thelamina propria, the muscularis mucosae, and the submucosa.
 15. Themethod of claim 1 wherein controlling the delivery of energy into thedepth of the tissue consists of ablating a fraction of tissue in theepithelial layer, the lamina propria, the muscularis mucosae, thesubmucosa, and the muscularis propria.
 16. The method of claim 1 whereincontrolling the delivery of radiofrequency energy across the tissuesurface and into tissue layers causes fractional ablation in tissuelayers of the gastrointestinal tract.
 17. The method of claim 1 whereindelivering energy includes delivering energy from an electrode patternconfigured circumferentially through 360 degrees around the ablationstructure.
 18. The method of claim 17 wherein delivering energy from theablation structure includes transmitting energy asymmetrically throughthe 360 degree circumference such that ablation is focused in an arc ofless than 360 degrees.
 19. The method of claim 1 delivering energyincludes delivering energy from an electrode pattern configuredcircumferentially through an arc of less than 360 degrees around theablation structure.
 20. The method of claim 1 further comprisingevaluating the target area at a point in time after the deliveringenergy step to determine the status of the area.
 21. The method of claim20 wherein the evaluating step occurs in close time proximity after thedelivery of energy, to evaluate the immediate post-treatment status ofthe site.
 22. The method of claim 20 wherein the evaluating step occursat least one day after the delivery of energy.
 23. The method of claim 1wherein the delivering energy step is performed more than once.
 24. Themethod of claim 1 further comprising: deriving energy for transmittingfrom an energy source that is controlled by a control system.
 25. Themethod of claim 24 wherein the energy source is a generator.
 26. Themethod of claim 24 further comprising feedback controlling the energytransmission so as to provide any of a specific power, power density,energy, energy density, circuit impedance, or tissue temperature. 27.The method of claim 1 further comprising: advancing an ablationstructure into the alimentary canal, the non-penetrating electrodepattern on the structure, the structure supported on an instrument;positioning the ablation structure adjacent to the target area; andmoving the ablation structure toward the surface of the target area tomake therapeutic contact on the target area prior to delivering energy.28. The method of claim 27 wherein the moving step includes inflating aballoon member.
 29. The method of claim 27 wherein the moving stepincludes expanding a deflection member.
 30. The method of claim 27wherein the moving step includes moving a deflection member.
 31. Themethod of claim 27 wherein the moving step includes expanding anexpandable member.
 32. The method of claim 27 further including aposition-locking step following the moving step.
 33. The method of claim32 the position-locking step includes developing suction between thestructure and the ablation site.
 34. The method of claim 27 furthercomprising evaluating the target area prior to the positioning step, theevaluating step to determine the status of the target area.
 35. Themethod of claim 27 wherein multiple target areas are being treated, themethod comprising the positioning, moving, and transmitting energy stepsto a first target area, and further comprises the positioning, moving,and transmitting energy steps to another target area without removingthe ablation structure from the patient.